title: Involvement of ethylene in gibberellic acid-induced sulfur assimilation, photosynthetic responses, and alleviation of cadmium stress in mustard.
abstract: The role of gibberellic acid (GA) or sulfur (S) in stimulation of photosynthesis is known. However, information on the involvement of ethylene in GA-induced photosynthetic responses and cadmium (Cd) tolerance is lacking. This work shows that ethylene is involved in S-assimilation, photosynthetic responses and alleviation of Cd stress by GA in mustard (Brassica juncea L.). Plants grown with 200 mg Cd kg(-1) soil were less responsive to ethylene despite high ethylene evolution and showed photosynthetic inhibition. Plants receiving 10 μM GA spraying plus 100 mg S kg(-1) soil supplementation exhibited increased S-assimilation and photosynthetic responses under Cd stress. Application of GA plus S decreased oxidative stress of plants grown with Cd and limited stress ethylene formation to the range suitable for promoting sulfur use efficiency (SUE), glutathione (GSH) production and photosynthesis. The role of ethylene in GA-induced S-assimilation and reversal of photosynthetic inhibition by Cd was substantiated by inhibiting ethylene biosynthesis with the use of aminoethoxyvinylglycine (AVG). The suppression of S-assimilation and photosynthetic responses by inhibiting ethylene in GA plus S treated plants under Cd stress indicated the involvement of ethylene in GA-induced S-assimilation and Cd stress alleviation. The outcome of the study is important to unravel the interaction between GA and ethylene and their role in Cd tolerance in plants.
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Asim
authors.initials: A
authors.lastname: Masood
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: M Iqbal R
authors.initials: MI
authors.lastname: Khan
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Mehar
authors.initials: M
authors.lastname: Fatma
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Mohd
authors.initials: M
authors.lastname: Asgher
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Tasir S
authors.initials: TS
authors.lastname: Per
authors.affiliation: Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India. Electronic address: naf9@lycos.com.
authors.forename: Nafees A
authors.initials: NA
authors.lastname: Khan
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D005030:Ethylenes / Q000494:pharmacology*; D005875:Gibberellins / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008190:Lyases / Q000378:metabolism; D009149:Mustard Plant / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects*; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D013430:Sulfate Adenylyltransferase / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D005030:Ethylenes; D005875:Gibberellins; D002104:Cadmium; D002734:Chlorophyll; D002245:Carbon Dioxide; D013455:Sulfur; C036216:ethylene; D006861:Hydrogen Peroxide; C007842:gibberellic acid; D013430:Sulfate Adenylyltransferase; D008190:Lyases; D012273:Ribulose-Bisphosphate Carboxylase; C021773:1-aminocyclopropanecarboxylate synthase
keywords: Antioxidant system; Ethylene; Gibberellic acid; Glutathione; Oxidative stress; Photosynthesis