Scholarly article on topic 'Allelopathic effect of Calotropis procera (Ait.) R. Br. on growth and antioxidant activity of Brassica oleracea var. botrytis'

Allelopathic effect of Calotropis procera (Ait.) R. Br. on growth and antioxidant activity of Brassica oleracea var. botrytis Academic research paper on "Biological sciences"

CC BY-NC-ND
0
0
Share paper
Keywords
{"Seedling length" / "Dry biomass" / "Relative water content" / "Chlorophyll content" / "Superoxide dismutase (SOD)" / "Peroxidase (POD) and catalase (CAT) activity"}

Abstract of research paper on Biological sciences, author of scientific article — Aasifa Gulzar, M.B. Siddiqui

Abstract The present study intended to investigate the effect of aqueous extract from Calotropis procera on the growth of Brassica oleracea var botrytis. Seeds of brassica were soaked in solutions containing 20%, 40%, 60% and 80% concentrations of leaf, fruit and flower extract of C. procera. For control, distilled water was used. The effects of extracts on germination percentage, seedling growth, dry biomass, and relative water content were investigated. Higher concentrations of extract (60% and 80%) significantly reduced germination percentage, radicle length, plumule length, dry matter accumulation, and relative water content of the brassica seedlings as compared to control. The retardatory effect increases with the increase in the concentration of three types of extract used, with more pronounced effect noticed by leaf extract followed by fruit and flower extract. There were significant interactions among the different concentrations of extracts used, etype of extract with respect to gemination percentage, seedling length, dry biomass, and relative water content. The effect of pot based assay in relation to chlorophyll content was significantly reduced and antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities] show both significant and non-significant effect on antioxidant enzymes based on concentrations of extract and extract type used. The antioxidant enzymes show the significant decrease in its activity at low concentrations (20% and 40%) and non-significant increase at higher concentration (60% and 80%) of extracts in contrast to control. Based on the investigation, it could be speculated that the delayed germination and low germination rate of the test species after treatment by extracts could be due to the fact that extracts damaged the membrane system of the seeds and C. procera might release phenolics into the soil and these are probably involved in the growth inhibitory effect of test species.

Academic research paper on topic "Allelopathic effect of Calotropis procera (Ait.) R. Br. on growth and antioxidant activity of Brassica oleracea var. botrytis"

Journal of the Saudi Society of Agricultural Sciences (2016) xxx, xxx-xxx

King Saud University Journal of the Saudi Society of Agricultural Sciences

www.ksu.edu.sa www.sciencedirect.com

n irljJII pq__lflU n IifjoIilB nipp^ll

SAUDI SOCIEIY FOB AGRICULTURAL SCIENCES

FULL LENGTH ARTICLE

Allelopathic effect of Calotropis procera (Ait.) R. Br. on growth and antioxidant activity of Brassica oleracea var. botrytis

Aasifa Gulzar *, M.B. Siddiqui

Department of Botany, A.M.U, Aligarh, U.P. 202002, India Received 5 February 2014; accepted 10 December 2015

KEYWORDS

Seedling length; Dry biomass; Relative water content; Chlorophyll content; Superoxide dismutase (SOD);

Peroxidase (POD) and catalase (CAT) activity

Abstract The present study intended to investigate the effect of aqueous extract from Calotropis procera on the growth of Brassica oleracea var botrytis. Seeds of brassica were soaked in solutions containing 20%, 40%, 60% and 80% concentrations of leaf, fruit and flower extract of C. procera. For control, distilled water was used. The effects of extracts on germination percentage, seedling growth, dry biomass, and relative water content were investigated. Higher concentrations of extract (60% and 80%) significantly reduced germination percentage, radicle length, plumule length, dry matter accumulation, and relative water content of the brassica seedlings as compared to control. The retardatory effect increases with the increase in the concentration of three types of extract used, with more pronounced effect noticed by leaf extract followed by fruit and flower extract. There were significant interactions among the different concentrations of extracts used, etype of extract with respect to gemination percentage, seedling length, dry biomass, and relative water content. The effect of pot based assay in relation to chlorophyll content was significantly reduced and antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities] show both significant and non-significant effect on antioxidant enzymes based on concentrations of extract and extract type used. The antioxidant enzymes show the significant decrease in its activity at low concentrations (20% and 40%) and non-significant increase at higher concentration (60% and 80%) of extracts in contrast to control. Based on the investigation, it could be speculated that the delayed germination and low germination rate of the test species after treatment by extracts could be due to the fact that extracts damaged the membrane system of the seeds and C. procera might release phe-nolics into the soil and these are probably involved in the growth inhibitory effect of test species. © 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

* Corresponding author at: Research scholar, Department of Botany, Aligarh Muslim University, Aligarh, India. Tel.: +91 9760931189. E-mail addresses: aasifa4gulzar@gmail.com, aasifa.gulzar@rediffmail.com (A. Gulzar). Peer review under responsibility of King Saud University.

Production and hosting by Elsevier

http://dx.doi.org/10.1016/jjssas.2015.12.003

1658-077X © 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

Allelopathy is fascinating and perplexing subject that concern with the interaction of plants as influenced by the chemical substances that they release into the environment (Bais et al., 2003; Machado, 2007; Willis, 2004). Allelochemicals from plants are released into the environment by exudation from roots, leaching from stems and leaves or decomposition of plant material (Rice, 1984; Inderjit et al., 2006). The multiple effects resulting from allelochemicals include effect on cell division, production of plant hormones, membrane permeability, germination of pollen grains, mineral uptake, movement of stomata, pigment synthesis, photosynthesis, respiration, protein synthesis, nitrogen fixation, and specific enzyme activities (El-Khatib et al., 2004; Rafael et al., 2005; Jamali et al., 2006; Hegazy et al., 2007; Farrag, 2007; Zeng et al., 2008; Inderjit et al., 2008; Pisula and Meiners, 2010; Kim and Lee, 2011; Djurdjevic et al., 2012; Mansour, 2013). Allelopathic potential of many crop plant and weeds have been investigated against different crops (Kato-Noguchi and Tanaka, 2006; Farooq et al., 2008; Jabran et al., 2010; Gulzar and Siddiqui, 2014). These plants release different types of water soluble phytotox-ins in their surrounding environment and in soil thereby inhibiting the germination and growth of different crops (Kadioglue et al., 2005; Singh et al., 2005; Batish et al., 2007). These allelochemicals can be used as potential source for natural herbicides, pharmaceuticals and biological control agents (Hirai, 2003; Cheema et al., 2004; Norton et al., 2008; Jabran et al., 2008; Razzaq et al., 2012; Macias et al., 2007).

To defend with stress conditions, Plants are equipped with several ROS scavenging enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and gua-iacol peroxidase (POX) which are activated to buttress plant strength against abiotic and biotic stresses. Reactive oxygen species are produced in huge amounts in plants upon exposure to stressful conditions such as sub-optimal temperature, high light, salt, and pathogen infection (Yamamoto et al., 2003; Halliwell, 2006). Enhanced activity of ROS-scavenging enzymes along with increased degree of membrane lipid perox-idation by allelochemical stress has been studied by several authors (Baziramakenga et al., 1995; Yu et al., 2003; Lara-Nunez et al., 2006; Ye et al., 2004, 2006).

Calotropis procera, known as apple of Sodom or mudar, is a member of family Asclepiadaceae (Parihar et al., 2011). The milky sap of this plant is known to contain three toxic glyco-sides: (i) calotropin, (ii) uscharin, and (iii) calotoxin as well as steroidal heart poisons, known as cardiac aglycones (Zeng et al., 2008). The plant also received much attention from researchers due to its allelopathic behavior and has extensively been used for the control of many plants. A number of secondary metabolites have been isolated from this plant that include many flavonoids (Heneidak et al., 2006; Srivastava et al., 2012), cardiac glycosides (Hanna et al., 2002), triterpenes (Bhutani et al., 1992) and sterols (Chundattu et al., in press) that might contribute its allelopathic potential. However, previous studies investigated regarding its phytotoxic and allelo-pathic effects of this plant in various crops have been carried out by (Kayode, 2004; Samreen et al., 2009; Yasin et al., 2012; Gulzar et al., 2014a; 2015). Its widespread and persistent occurrence near barley, oat, rice, sorghum, maize, cotton, sugarcane fields and especially around wheat crop fields makes it

suspicious to cause some adverse effect on these crops through allelopathic interaction (Yasin et al., 2012). Therefore there is always a threat that it may become a major weed of our cropping system. Keeping in view these facts, a study was planned to evaluate the phytotoxic effect of C. procera on germination, seedling growth, dry biomass, total chlorophyll content and antioxidant enzymes (SOD, POD, CAT activity) of B. oleracea.

2. Materials and methods

2.1. Preparation of aqueous extract

Insect-free, disease-free plants of C. procera were collected from the campus of Aligarh Muslim University, Aligarh (27°, 29-28°, 100 N.L and 77°, 29-78°, 38° E.L) where it was growing abundantly. They were washed thoroughly with distilled water and air-dried at room temperature for 96 h. The leaf, fruit and flower portions were separated, chopped into 1-cm long pieces, and were kept in the oven at 28 °C for 72 h. The dried sample was then crushed in a mortar and pestle to make powder. Powdered materials of each part (8g) were added into 100 ml distilled water (1:8 w/v) and kept in shaker for 1hour. After shaking for an hour, extracts were placed at room temperature for 48 hours following the method of Wardle et al. (1992). The extracts were then filtered with muslin cloth followed by Whatman filter paper No. 1. This served as the stock solution from which other concentrations (20%, 40%, and 60%) were prepared by way of dilution.

2.2. Determination ofgermination percentage, root length, shoot length, dry biomass and relative water content (RWC)

The seed of B. oleracea was procured from IARI, New Delhi. These were surface sterilized with 95% ethanol and 10% chlo-rax for 5 min and thoroughly washed with sterile water several times. Next, five sets of autoclaved petri dishes were prepared, each containing a single layer of Whatman No. 1 filter paper and 5 ml of test extract for each concentration (20%, 40%, 60%, and 80%) of leaf, fruit, and flower. The petri dishes treated with distilled water were taken as a control. In each prepared petri dish, ten surface sterilised brassica seeds were placed. A total of four replications of the sets with the previously described concentrations were kept undisturbed at room temperature (24 ± 2°C) in the laboratory for seven days. The number of germinating seeds was recorded on the sixth day, whereas root length, shoot lengths, dry biomass and RWC of the brassica seedlings were determined after fifteen days. The emergence of a radical approximately 1 mm in diameter was taken as the index of germination. The dry biomass was determined after oven drying at 80 °C for 24 hours. Using the equation of Deef and Abd El-Fattah (2008), the relative water content (RWC) was evaluated as: RWC% = (FW - DW)/FW x 100.

2.3. Determination of chlorophyll and antioxidant enzymes

To observe the direct effect of allelochemicals on crop in the field, 20-cm pots were filled with 300g of soil collected from brassica-growing fields. Ten surface-sterilised brassica seeds

were sown approximately 5 mm deep in each pot. The pots were divided into two sets. Set first, received a daily dose of 50 ml of extract of leaf, fruit and flower of various concentrations (20%, 40%, 60%, and 80%). The control set was treated with distilled water. All of the pots were kept in bright sunlight and three replications were conducted for each treatment. After twenty days, the seedlings were uprooted from each pot, keeping the root system intact. They were washed under slow-flowing tap water until the adhering soil particles were removed and then soaked between paper towels. Samples were freeze dried for physiological and antioxidant analysis.

2.4. Assays for activity of superoxide dismutase (SOD)

SOD activity was determined by photochemical method as described by Giannopolitis and Ries, 1977; Gulzar and Siddiqui, 2015.

2.5. Assay for peroxidase activity (POD)

б 60-

Flower extract Fruit extract Leaf extract

Control 20% 40% 60% 80%

Treatment (%)

Figure 1 The effects of increasing concentrations of different organ extracts of C. procera on the germination percentage of brassica. The bars indicate standard deviation.

POD activity was determined by the method of Vetter et al. (1958) as modified by Gorin and Heidema (1976); Gulzar and Siddiqui, 2015.

2.6. Assays for catalase activity (CAT)

Catalase activity (CAT) was measured according to Cakmak and Marschner, 1992; Gulzar and Siddiqui, 2015.

2.7. Determination of chlorophyll content

Total Chlorophyll contents of fresh leaves of brassica were determined by the method of Arnon (1949).

2.8. Statistical analysis

All experiments were performed in a completely randomized manner. The data of germination percentage, seedling growth, dry biomass and relative water content were performed with SPSS/PC software ver. 16.0 (SPSS Inc., Illinois). In Figs. 1-6, showing change in these parameters, the bars represent the standard deviation of measurements. The data of antioxidant enzymes were analyzed by one-way analysis of variance, the treatment means separated from the control at p < 0.05 and comparisons were made using Duncan, s multiple range test (Ducan, 1955).

3. Results

Aqueous extract from all parts significantly reduced the germination percentage, root length, shoot length, dry biomass, relative water content and chlorophyll content of brassica seedlings. The reduction in germination percentage varies with the type of extract and with the increasing concentration. At 80% concentration of leaf extract, it was reduced by (52%), and at same concentration of fruit and flower extract, it was reduced by (46%) and (32%) (Fig. 1). The reduced significant trend in root and shoot length of brassica seedling occurs more at 80% followed by 60%, 40% and 20%. The percentage reduction in shoot length and root length observed at 80%

Flower extract Fruit extract Leaf extract

26 1 24 -

| 20 -

H 18 -

rn 16 -

£ 1412 -10 -

8 -I-1-1-1-1-1-

Control 20% 40% 60% 80%

Treatment (%)

Figure 2 The effects of increasing concentrations of different organ extracts of C. procera on the plumule length of brassica. The bars indicate standard deviation.

and 20% of leaf extract was (41.55%), (13.36%), (27.08%), (8.57%) (Figs. 2 and 3). The dry biomass reduction significantly noticed more at 80% of all extract types, but the retardatory effect varies with extract type, more in leaf extract reduced by (40%) followed by fruit extract and flower extract (Fig. 4). Present investigation showed that RWC decreased significantly in brassica seedlings in response to the application of three types of extract. Maximum significant decrease in RWC was recorded with leaf aqueous extracts at higher concentration (80%) (Fig. 5). During present investigation, there was found that three types of extracts significantly decreased the amount of chlorophyll content. Maximum significant decrease in chlorophyll content was found with leaf extract at 80% as compared to control (Fig. 6). The result of the present work indicated that peroxidase activity decreased in brassica receiving leaf, fruit and flower extracts. Maximum significant decrease in activity of POD was found with lower aqueous extract (20% and 40%) of leaf extract. However, higher concentration of leaf extract (60% and 80%) non-significantly

Flower extract - Fruit extract Leaf extract

20% 40% 60%

Treatment (%)

Figure 3 The effects of increasing concentrations of different organ extracts of C. procera on the radicle length of brassica. The bars indicate standard deviation.

Flower extract - Fruit extract Leaf extract

Control 20% 40% 60% 80%

Treatment (%)

Figure 5 The effects of increasing concentrations of different organ extracts of C. procera on the chlorophyll content of brassica. The bars indicate standard deviation.

Control

Fruit extract Flower extract Leaf extract

Control

20% 40%

Treatment (%)

Figure 4 The effects of increasing concentrations of different organ extracts of C. procera on the dry biomass of brassica. The bars indicate standard deviation.

66 -64 -62 -60 -

50 -48 -46

Flower extract Fruit extract Leaf extract

20% 40% 60%

Treatment (%)

Figure 6 The effects of increasing concentrations of different organ extracts of C. procera on the relative water content of brassica. The bars indicate standard deviation.

Ü 56 -

Control

increased the accumulation of peroxidase (Table 1). Same trend also observed with fruit and flower extract. Maximum non-significant increase in catalase activity (CAT) was recorded in brassica leaves receiving higher concentration of leaf extract (80% and 40%) in comparison with untreated control. Maximum significant decrease in CAT was recorded with lower aqueous extract (20%) of leaf extract as compared with untreated control (Table 1) The application of leaf, fruit and flower aqueous extracts non-significantly increased the level of super oxide dismutase activity at higher concentration (60% and 80%) and significantly decreased the level of SOD activity at lower concentration (20% and 40%) in contrast to control (Table 1).

4. Discussion

Aqueous extracts of various concentrations of leaf, fruit, and flower of C. procera had varying degrees of inhibition on the germination and growth of mustard seeds, reflecting the allelo-pathic potential of the plant. Higher inhibition was observed with leaf extract at higher concentration. Lowering germination rate as a result of allelochemical stress may be due to inhibition of water uptake (Tawaha and Turk, 2003) and alteration in the activity of gibberellic acid (Olofsdotter, 1998) which is known to regulate de novo amylase production during germination process (Chandler et al., 1984). However, Singh et al. (2009) observed a stimulation of amylase activity

Table 1 Allelopathic impact of different concentrations of different parts of C. procera on antioxidant activity of brassica. Each value is a mean of four replicates with standard error.

Extract type

Treatment (%)

Superoxide dismutase (SOD) (units/g F.W)

Peroxidase (POD) content (units/min)

Catalase (CAT) content (units/min)

Leaf extract

Fruit extract

Flower extract

Control 34 ± 2.5ab 0.8 ± 0.11abc 14.5 ± 0.89bcd

20% 32 ± 1.4bd 0.6 ± 0.06bc 12.4 ± 0.72e

40% 30 ± 3.9c 0.4 ± 0.34d 10.5 ± 0.87f

60% 42 ± 3.2ae 0.12 ± 0.20a 15.2 ± 0.59a

80% 44 ± 2.7ag 0.14 ± 0.35e 16.0 ± 0.78bd

Control 34 ± 3.2ab 0.8 ± 0.11a 14.5 ± 0.97ae

20% 30 ± 5.2c 0.7 ± 0.58a 14.5 ± 1.30bc

40% 29 ± 3.8d 0.5 ± 0.32bd 11.2 ± 2.80ba

60% 38 ± 3.8de 0.10 ± 0.15de 17.2 ± 0.28abc

80% 40 ± 6.6f 0.11 ± 0.26gh 19.8 ± 0.21dc

Control 34 ± 0.3gh 0.8 ± 0.10h 14.5 ± 0.74ed

20% 28 ± 4.4a 0.5 ± 0.47 cc 0.9 ± 1.08 fg

40% 27 ± 2.3bc 0.2 ± 0.48efg 0.7 ± 1.44ab

60% 36 ± 9.8ab 0.13 ± 0.17adc 13.5 ± 1.11b

80% 40 ± 4.4ad 0.10 ± 0.12de 11.6 ± 0.95 cd

Values followed by the same letters within each column are not significantly different at 0.05 (ANOVA and Duncan's multiple range test).

in maize seedlings by lower leachate concentration of Nicotiana, which possible might be due to increased level of GA. Cell division and elongation, which are growth prerequisite, are known to be inhibited by allelochemical. The inhibition of seed germination was found to be concentration-dependent (Oudhia, 1999). Kordali et al. (2006) reported that essential oils of Achillea biebersteinii had inhibitory effects on seed germination and seedling growth of Amaranthus retroflexus, crisium arvense and Lactuca serriola. Root growth is highly susceptible to the presence of allelo-chemicals in the rhizosphere (Baziramakenga et al., 1995) due to the fact that root tissues are more permeable to allelo-chemicals that do shoot tissues Nishida et al. (2005) which therefore may impair root metabolic activities and cell division in root tips. Dry weight reduction may be due to phytotoxic effect of proteases present in C. procera extract (Singh et al., 2010). These results are corroborated by the work of Sanginga and Swift (1992) and Khan et al. (1999) who reported reduction in Z. mays shoot dry biomass by eucalyptus extracts. Similar findings have been communicated by Ahn et al. (2005) who demonstrated the inhibition in dry biomass, leaf area, plant height due to allelopathic potential of rice germplasm for control of E. crusgalli. The results of study applied by Benyas et al. (2010) indicated that water extract of Xanthium strumarium L. in concentrations of 0%, 1%, 1.5% and 2% shows no considerable effect on the germination rate, rootlet length, dry weight of stemlet and rootlet and the gradient of the lentil chlorophyll but in the higher concentrations negative effects have been observed which are in compliance with the results of this study. All concentrations of leaf extract affected RWC of brassica seedlings more than the extracts taken from fruit and flower which is consistent with Yang et al. (2004) and Gulzar et al. (2014b) that depict that macro- and micronutrient absorption and IAA oxidase in plant root cells is inhibited by various allelochemicals which may lead to the observed reductions in DW, FW, and RWC. In the present result there occurs the significant reduction of chlorophyll content seen with all concentrations. Reduction

in Chlorophyll content was previously reported as a result of allelochemical stress (Singh et al., 2009; Ervin and Wetzel, 2000; Moradshahi et al., 2003; Gulzar and Siddiqui, 2014) which could be attributed to the inhibition of chlorophyll biosynthesis (inhibition of supply orientation) and/or the stimulation of chlorophyll degradation (stimulation of consumption orientation) (Yang et al., 2004, 2002). Siddiqui (2007) reported reduction in chlorophyll content of Vigna mungo due to the allelochemicals present in leachate of black pepper which possibly target enzymes responsible for the conversion of porphyrin precursors. In this comparative study, though all three organs showed significant allelopathic potential, the degree of inhibition seemed to be highest in the case of the leaf extract of C. procera.

During current investigation, the level of antioxidant enzymes either increased or decreased by the application of leaf, fruit and flower extracts. The observed negative impact on the above mentioned parameters is due to the presence of large amounts of phenolics in the plant which follows the trend Leaves > Fruit > Flower. The presence of pheno-lics and flavonoids has been investigated by (Srivastava et al., 2012). Many plants are reported to increase the level of antioxidant enzymes in response to environmental stresses because both biotic and abiotic stresses are responsible for the production of reactive oxygen species (ROS) (Dat et al., 2000). The increase in antioxidant activity in response to different stresses has been reported previously by Bor et al. (2003). Incensement in SOD activity in our results is same as reported by Gomez et al. (2004) who found an increase in all SOD enzymes of pea chloroplast following a long term of Nacl treatments. According to Koca et al. (2007) salinity leads to decrease in SOD activity in salt sensitive plants of Sesame indicum L. than salt tolerant ones (Akbar et al., 2009). SOD scavenges the highly reactive free radicals by converting them into H2O2. Although H2O2 is equally toxic, H2O2 is further reduced to H2O by CAT in the peroxisomes, by APX in the chloroplast and cytosol, and by GPX in the cell wall (Blokhina et al., 2003). The induction of peroxidase

(POD) activity in plants occurs in response to many biotic and abiotic stresses (Casal et al., 1994). Peroxidase (POD) is believed to play an important role in auxin catabolism, the oxidation of phenolics to form lignin, the cross-linking of hydroxyl proline-rich glycol proteins in plant cell walls, and the production and breakdown of hydrogen peroxide and other reactive oxygen species (Klotz and Lagrimini, 1996). The roles that POD can play in cell wall toughening and in the production of toxic secondary metabolites and its simultaneous oxidant and anti-oxidant capabilities can make it an important factor in the integrated defense response of plants to variety of stresses (Felton et al., 1989). An increase in Catalase activity has been reported in other studies on allelochemicals mode of action, that is, fer-ulic acid increased Catalase activity in maize seedlings (Devi and Prasad, 1996) and benzoic acid in cucumber cotyledons (Maffi et al., 1999).Although evidence about allelochemical-induced oxidative stress together with increased activity of antioxidant enzymes is emerging (Politycka, 1996; Rafael et al., 2005; Baziramakenga et al., 1995; Yu et al., 2002; Ye et al., 2006) however, little information is available about the mechanisms by which allelochem-icals induce ROS formation. Many studies have shown that increased plasma membrane NAD(P)H oxidase activity was associated with increased O2 and H2O2 production following biotic and abiotic stresses (Keller et al., 1998; Forman et al., 2002; Lara-Nunez et al., 2006). From our results it can be inferred that extracts posses some allelochemicals which might have significantly and non-significantly increased and decreased the antioxidant enzyme activity in brassica.

5. Conclusion

In conclusion, the extract of the weed C. procera inhibited the germination and seedling growth of brassica due to its phyto-toxic effects. Hence, if present in field, this weed can disturb the stand establishment of brassica plant. There is a need to take a serious notice of the presence of this weed in the crop fields and nearby places. Further research can explore the alle-lochemicals present in C. procera as well as the complex allelo-pathic mechanisms through which this phytotoxic plant disturbs the neighboring plants.

Acknowledgment

We are thankful to the University Grants Commission, New Delhi, for providing the financial assistance to carry out this research study.

References

Ahn, J.K., Hahn, S.J., Kim, J.T., Khan, T.D., Chung, I.M., 2005. Evaluation of allelopathic potential among rice (Oryza sativa L.) germplasm for control of Echinochloa crusgalli P. Beauv in the field. J. Crop Prot. 24, 413-419. Akbar, F., Yousaf, N., Rabbani, M.A., Shinwari, Z.K., Masood, M. S., 2009. Study of total seed proteins pattern of sesame (Sesamum indicum L.) landraces via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Pak. J. Bot. 44, 2009-2014. Arnon, D.I., 1949. Copper enzymes in isolated chloroplast polyphenol oxidase in Beta vulgaris. Plant Physiol. 24, 1-15.

Bais, HP., Vepachedu, R., Gilroy, S., Callaway, R.M., Vivanco, J.M., 2003. Allelopathy and exotic plant invasion: From molecules and genes to species interactions. Science 301, 1377-1380.

Batish, D R., Lavanya, K., Singh, H.P., Kohli, R.K., 2007. Root mediated allelopathic interference of Nettle-leaved Goosefoot (Chenopodium murale) on wheat (Triticum aestivum L.). J. Agron. Crop Sci. 193, 37-44.

Baziramakenga, R., Leroux, G.D., Simard, R.R., 1995. Effects of benzoic and cinnamic acids on membrane permeability of soybean roots. J. Chem. Ecol. 21, 1271-1285.

Benyas, E., Hassanpouraghdam, M.B., Zehtabsalmasi, S., Khatamian Oskooei, O.S., 2010. Allelopathic effects of Xanthium strumarium L. shoot aqueous extract on germination, seedling growth and chlorophyll content of lentil (Lens Culinaris Medic.). Rom. Biotechnol. Lett. 15, 5223-5228.

Bhutani, K.K., Gupta, D.K., Kapil, R.S., 1992. Occurrence of D/E trans stereochemistry isomeric to ursane (cis) series in a new pentacyclic triterpene from Calotropis procera. Tetr. Lett. 33, 75937596.

Blokhina, O., Virolainen, E., Fagerstedt, K.V., 2003. Antioxidants, oxidative damage and oxygen deprivation stress. A review. Ann. Bot. 91, 179-194.

Bor, M., Ozdemir, F., Turkan, I., 2003. The effect of salt stress on lipid peroxidation and antioxidants in leaves of sugar beet (Beta vulgaris L.) and wild beet (Beta maritime L.). Plant Sci. 164, 77-84.

Cakmak, I., Marschner, H., 1992. Magnesium deficiency and high light intensity enhance distribution of sorgoleone in grain sorghum germplasm. J. Agric. Food Chem. 44, 1343-1347.

Casal, J., Malla, R.A., Ballare, C.L., Maldonado, S., 1994. Phy-tochrome mediated effects on extracellular peroxidase activity, lignin content and bending resistance in etiolated Vicia faba epicotyls. Physiol. Plant. 92, 555-562.

Chandler, P.M., Zucar, J.A., Jacobson, J.V., Higgins, T.J.V., Inglis, A. S., 1984. The effect of gibberellic acid and abscisic acid on a-amylase mRNA levels in barley aleurone layers studies using an a-amylase c DNA clone. Plant Mol. Biol. 3, 407-408.

Cheema, Z.A., Khaliq, A., Saeed, S., 2004. Weed control in maize (Zea mays L.) through sorghum allelopathy. J. Sustain. Agric. 23, 73-86.

Chundattu, S.J., Agrawal, V.K., Ganesh, N., 2012. Phytochemical investigation of Calotropis procera. Arab. J. Chem. (in press).

Dat, J., Vandenabeele, S., Vranova, E., Van Montagu, M., Inze, D., Van Breusegem, F., 2000. Dual action of the active oxygen species during plant stress responses. Cell Mol. Life Sci. 57, 779-795.

Deef, H.E., Abd El-Fattah, R.I., 2008. Allelopathic effects of water extract of Artemisia princeps var. orientalis on wheat under two type of soils. Acad. J. Plant Sci. 1, 12-17.

Devi, R., Prasad, M.N.V., 1996. Ferulic acid mediated changes on oxidative enzymes of maize seedlings-implication of growth. Biol. Plant. 38, 387-395.

Djurdjevic, L., Gajic, G., Kostic, O., Jaric, S., Pavlovic, M., Mitrovic, M., 2012. Seasonal dynamics of allelopathically significant phenolic compounds in globally successful invader Conyza canadensis L. plants and associated sandy soil. Flora 207, 812-820.

Ducan, D.B., 1955. Multiple range and multiple F-tests. Biometrics 11, 1-42.

El-Khatib, A.A., Hegazy, A.K., Galal, H.K., 2004. Allelopathy in the rhizosphere and amended soil of Chenopodium murale L. Weed Biol. Manage. 4, 35-42.

Ervin, G.N., Wetzel, R.G., 2000. Allelochemical autotoxicity in the emergent wetland macrophyte Juncus effuses (Juncaceae). Am. J. Bot. 87, 853-860.

Farooq, M., Jabran, K., Rehman, H., Hussain, M., 2008. Allelopathic effects of rice on seedling development in wheat, oat, barley and berseem. Allelopathy J. 22, 385-390.

Farrag, H.F., 2007. Allelopathic potential of some invasive weeds in Egypt. Ph.D. Thesis, Botany Department, Faculty University, Cairo University.

Felton, G., Donato, W.K., Del, R.J., Vecchio, Duffey, S., 1989. Activation of plant foliar oxidases by insect feeding reduces nutritive quality of foliage for noctuid herbivores. J. Chem. Ecol. 15, 2667-2694.

Forman, H.F., Torres, M., Fukuto, J., 2002. Redox signaling. Mol. Cell Biochem. 234, 49-62.

Giannopolitis, N., Ries, S.K., 1977. Superoxide dismutase: I Occurrence in higher plants. Plant Physiol. 59, 309-314.

Gomez, J.M., Jimenez, A., Olmos, E., Sevilla, P., 2004. Location and effect of long term Nacl stress on superoxide dismutase and ascorbic peroxidase isozyme of pea chloroplast. J. Bot. 55, 119-130.

Gorin, N., Heidema, F.T., 1976. Peroxidase activity in golden delicious apples as a possible parameter of ripening and senescence. J. Agric. Food Chem. 24, 200-201.

Gulzar, A., Siddiqui, M.B., 2014. Evaluation of allelopathic effect of Eclipta alba (L.) Hassk on biochemical activity of Amaranthus spinosus L., Cassia tora L. and Cassia sophera L. Afr. J. Environ. Sci. Technol. 8, 1-5.

Gulzar, A., Siddiqui, M.B., 2015. Root-mediated allelopathic interference of bhringraj (Eclipta alba L.) Hassk. on peanut (Arachis hypogaea) and mung bean (Vigna radiata). App. Soil Ecol. 87, 7280.

Gulzar, A., Siddiqui, M.B., Arerath, U., 2014a. Phytotoxic effects of Calotropis procera (Ait.) R. Br. extract on three weed plants. Analele Universitatii din Oradea, Fascicula Biologie 21 (2), 57-64.

Gulzar, A., Siddiqui, M.B., Bi, S., 2014b. Assessment of allelopathic potential of Cassia sophera L. on seedling growth and physiological basis of weed plants. Afr. J Biotech. 13 (9), 1037-1046.

Gulzar, A., Siddiqui, M.B., Bi, S., 2015. Phenolic acid allelochemicals induced morphological, ultrastructural and cytological modification on Cassia sophera L. and Allium cepa L. Protoplasma. http:// dx.doi.org/10.1007/s00709-015-0862-x.

Halliwell, B., 2006. Reactive species and antioxidants, Redox biology is a fundamental theme of aerobic life. Plant Physiol. 141, 312-322.

Hanna, A.G., Shalaby, N.M.M., Morsy, N.A.M., Andras, A., Toth, G., Malik, S., Duddeck, H., 2002. Structure of a calotropagenin-derived artifact from Calotropis procera. Magn. Res. Chem. 40, 599-602.

Hegazy, A.K., Goda, S.K., Farrag, H.F., 2007. Protein expression of some cultivated and weed plants in response to invasive plant mulching. Global J. Mol. Sci. 2, 1-7.

Heneidak, S., Grayer, R.J., Kite, G.C., Simmonds, M.S.J., 2006. Flavonoid glycosides from Egyptian species of the tribe Asclepi-adeae (Apocynaceae, subfamily Asclepiadoideae). Biochem. Sys. Ecol. 34, 575-584.

Inderjit, Seastedt, T.R., Callaway, R.M., Pollock, J.I., Kaur, J., 2008. Allelopathy and plant invasions: traditional, congeneric, and biogeographical approaches. Biol. Invasions 10, 875-890.

Inderjit, Callaway, R.M., Vivanco, J.M., 2006. Can plant biochemistry contribute to understanding of invasion ecology? Trends plant science 11, 1360-1385.

Jabran, K., Farooq, M., Hussain, M., Rehman, H., Ali, M.A., 2010. Wild oat (Avena fatua L.) and canary grass (Phalaris minor Ritz.) management through allelopathy. J. Plant Protec. Res. 50, 32-35.

Jabran, K., Cheema, Z.A., Farooq, M., Basra, S.M.A., Hussain, M., Rehman, H., 2008. Tank mixing of allelopathic crop water extracts with pendimethalin helps in the management of weeds in canola (Brassica napus) field. Int. J. Agric. Biol. 10, 293-296.

Jamali, A., Kouhila, M., Ait Mohamed, L., Jaouhari, J.T., Idlimam, A., Abdenouri, N., 2006. Sorption isotherms of Chenopodium ambrosioides leaves at three temperatures. J. Food Eng. 72, 77-84.

Kadioglue, Yanar, Y., Asav, U., 2005. Allelopathic effect of weed leachates against seed germination of some plants. J. Environ. Biol. 26, 169-173.

Kato-Noguchi, H., Tanaka, Y., 2006. Abscisic acid-glucose ester as an allelopathy agent from citrus fruit. Acta Physiol. Plant. 28, 635639.

Kayode, J., 2004. Allelopathic effect of aqueous extracts of Calotropis procera on germination and seedling growth of maize. Pak. J. Sci. Ind. Res. 47, 69-72.

Keller, T., Damude, H.G., Werner, D., Doerner, P., Dixon, R.A., Lamb, C., 1998. A plant homolog of the neutrophil NADPH oxidase gp91(phox) subunit gene encodes a plasma membrane protein with Ca2+ binding motifs. Plant Cell 10, 255-266.

Khan, M.A., Mamoon-ur-Rashid, Baloch, M.S., 1999. Allelopathy of eucalyptus on maize crop. Sarhad J. Agric. 15, 393-397.

Kim, Y.O., Lee, E.J., 2011. Comparison of phenolic compounds and the effects of invasive and native species in East Asia: support for the novel weapons hypothesis. Ecol. Res. 26, 87-94.

Klotz, K.L., Lagrimini, L.M., 1996. Phytohormone control of the tobacco anionic peroxidase promoter. Plant Mol. Biol. 31, 563573.

Koca, M., Bor, M., Özdemir, F., Turkan, I., 2007. The effect of salt stress on lipid peroxidation, antioxidative enzymes and proline content of sesame cultivars. Environ. Exp. Bot. 60, 344-351.

Kordali, S., Cakir, A., Akcin, T.A., Mete, E., Akcin, A., Ozkan, H., Sokmen, M., Ozbek, T., 2006. Antifungal and activities of the essential oil and n-hexane extracts of Achillea gypsicola Hub-Mor. and Achillea biebersteinii Afan. (Asteraceae). Indust. Crops Prod. 29, 562-570.

Lara-Nunez, A., Romero-Romero, T., Ventura, J.L., Blancas, V., Anaya, A.L., Cruz-Ortega, R., 2006. Allelochemical stress causes inhibition of growth and oxidative damage in Lycopersicon esculentum Mill. Plant Cell Environ. 29, 2009-2016.

Machado, S., 2007. Allelopathic potential of various plant species on downy brome: implications for weed control in wheat production. Agron. J. 99, 127-132.

Macias, F.A., Molinillo, J.M.G., Varela, R.M., Galindo, J.C.G., 2007. Allelopathy: a natural alternative for weed control. Pest Manage. Sci. 63, 327-348.

Maffi, M., Bertea, C.M., Garneri, F., Scanneri, S., 1999. Effect of benzoic acid hydroxyl and methoxy ring substituents during cucumber (Cucumis sativus L.) germination, Isocitratelyase and catalase activity. Plant Sci. 141, 139-147.

Mansour, M.M.F., 2013. Plasma membrane permeability as an indicator of salt tolerance in plants. Rev. Biol. Plant. 57, 1-10.

Moradshahi, A., Ghadiri, H., Ebarhimikia, F., 2003. Allelopathic effects of crude volatile oil and aqueous extracts of Eucalyptus camaldulensis Dehnh. leaves on crops and weeds. Allelopath. J. 12, 189-196.

Razzaq, A., Cheema, Z., Jabran, K., Hussain, M., Farooq, M., Zafar, M., 2012. Reduced herbicide doses used together with allelopathic sorghum and sunflower water extracts for weed control in wheat. J. Plant Prot. Res. 52, 281-285.

Hirai, N., 2003. Application of allelochemicals to agriculture. Biol. Sci. Space 17, 4-5.

Nishida, N., Tamotsu, S., Nagata, N., Saito, C., Sakai, A., 2005. Allelopathic effects of volatile monoterpenoids produced by Salvia leucophylla: inhibition of cell proliferation and DNA synthesis in the root apical meristem of Brassica campestris seedlings. J. Chem. Ecol. 31, 1187-1203.

Norton, A.P., Blair, A.C., Hardin, J., Nissen, S.J., Brunk, G.R., 2008. Herbivory and novel weapons: No evidence for enhanced competitive ability or allelopathy induction of Centurea diffusa by biological control. Biol. Invasions 10, 79-88.

Olofsdotter, M., 1998. Allelopathy in rice. In: Olofsdotter, M. (Ed.). Proceeding of the Workshop on Allelopathy in Rice, 25-27 November 1996. Manila, Philippines, International Rice Research Institute

Oudhia, P., 1999. Allelopathic effects of some obnoxious weeds on germination of Melilotus alba. Legume Res. 22, 133-134.

Parihar, G., Sharma, A., Ghule, S., Sharma, P., Deshmukh, P., Srivastava, D.N., 2011. Anti-inflammatory effect of Calotropis procera root bark extract. Asian J. Pharm. Life Sci. 1, 29-44.

Pisula, N.L., Meiners, S.J., 2010. Relative allelopathic potential of invasive plant species in a young disturbed woodland. J. Torrey Bot. Soc. 13, 81-87.

Politycka, B., 1996. Peroxidase activity and lipid peroxidation in roots of cucumber seedlings influenced by derivatives of cinnamic and benzoic acids. Acta Physiol. Plant. 18, 365-370.

Yang, C.M., Lee, C.N., Chou, C.H., 2002. Effects of three allelopathic phenolics on chlorophyll accumulation of rice (Oryza sativa) seedlings: I. Inhibition of supply-orientation. Bot. Bull. Acad. Sin. 43, 299-304.

Rafael, V., Teodoro, M., Jose, L.Q., Pilar, P., Francisco, A., Hans, L., 2005. Variation in relative growth rate of 20 Aegilops species (Poaceae) in the field: the importance of net assimilation rate or specific leaf area depends on the time scale. Plant Soil 272, 11-27.

Rice, E.L., 1984, second ed.. In: Allelopathy Academic Press, Orlando, Florida, pp. 422.

Samreen, U., Hussain, F., Sher, Z., 2009. Allelopathic potential of Calotropis procera (AIT.) R. Br. Pak. J. Plant Sci. 15, 7-14.

Sanginga, N., Swift, M.J., 1992. Nutritional effects of eucalyptus litter on the growth of maize (Zea mays). Agric. Ecosyst. Environ. 41, 55-65.

Siddiqui, Z.S., 2007. Allelopathic effects of black pepper leachings on Vigna mungo (L.) Hepper. Acta Physiol. Plant. 29, 303-308.

Singh, A.N., Shukla, A.K., Jagannadham, M.V., Dubey, V.K., 2010. Purification of a novel cysteine protease, procerain B, from Calotropis procera with distinct characteristics compared to procerain. Process Biochem. 45, 399-406.

Singh, H.P., Batish, D.R., Shalinder, K., Kohli, R.K., Dogra, S.K., 2005. Allelopathic interference of Ageratum conyzoides L. against some crop plants. Weeds management: balancing people, planet, profit. In: Proc. 14th Aus. Weeds Conf., Wagga Wagga, New South Wales, Australia, 6-9 September 2004, pp. 558-561.

Singh, A., Singh, D., Singh, D.N., 2009. Allelochemical stress produced by aqueous leachate of Nicotiana plumbaginifolia Viv. Plant Growth Regul. 58, 163-171.

Srivastava, N., Chauhan, A.S., Sharma, B., 2012. Isolation and characterization of some phytochemicals from Indian traditional plants. Biotechnol. Res. Int. 1, 1-8.

Tawaha, A.M., Turk, M.A., 2003. Allelopathic effects of black musard (Brassica nigra) on germination and growth of wild barley (Hordeum spontaneum). J. Agron. Crop Sci. 189, 298-303.

Vetter, J.L., Steinberg, M.P., Nelson, A.I., 1958. Quantitative determination of peroxidase in sweet corn. J. Agric. Food Chem. 6, 3941.

Wardle, D.A., Nicholson, K.S., Ahmed, M., 1992. Comparison of osmotic and allelopathic effects of grass leaf extracts on grass seed germination and radical elongation. Plant Soil 140, 315-319.

Willis, R.J., 2004. Justus Ludewig Von Uslar, and the First Book On Allelopathy. Springer, 3300 AA Dordrecht, The Netherland, pp. 1.

Yamamoto, Y., Kobayashi, Y., Devi, S.R., Rikiishi, S., Matsumono, H., 2003. Oxidative stress triggered by aluminum in plant roots. Plant Soil 255, 239-243.

Yang, C.M., Chang, I.F., Lin, S.J., Chou, C.H., 2004. Effects of three allelopathic phenolics on chlorophyll accumulation of rice (Oryza sativa) seedlings: II. Stimulation of consumption-orientation. Bot. Bull. Acad. Sin. 45, 119-125.

Yasin, M., Safdar, M.E., Iqbal, Z., Ali, A., Jabran, K., Tanveer, A., 2012. Phytotoxic effects of Calotropis procera extract on germination and seedling vigor of wheat. Pak. J. Weed Sci. Res. 18, 379392.

Ye, S.F., Yu, J.Q., Peng, Y.H., Zheng, J.H., Zou, L.Y., 2004. Incidence of Fusarium wilt in Cucumis sativus L. is promoted by cinnamic acid, an autotoxin in root exudates. Plant Soil 263, 143150.

Ye, S.F., Zhou, Y.H., Sun, Y., Zou, L.Y., Yu, J.Q., 2006. Cinnamic acid causes oxidative stress in cucumber roots, and promotes incidence of Fusarium wilt. Environ. Exp. Bot. 56, 255-262.

Yu, J.Q., Shou, S.Y., Qian, Y.R., Hu, W.H., 2002. Autotoxic potential in cucurbit crops. Plant Soil 223, 147-151.

Yu, J.Q., Ye, S.F., Zhang, M.F., Hu, W.H., 2003. Effects of root exudates, aqueous root extracts of cucumber (Cucumis sativus L.) and allelochemicals on photosynthesis and antioxidant enzymes in cucumber. Biochem. Syst. Ecol. 31, 129-139.

Zeng, R.S., Mallik, A.U., Luo, S.M., 2008. Allelopathy in sustainable agriculture and forestry: allechemicals in plants (Chapter 4). Springer Science & Business Media, part 2, 63-104.