title: Brassinosteroids protect photosynthetic machinery against the cadmium induced oxidative stress in two tomato cultivars.
abstract: The present study was conducted with an aim to gain better insight of brassinosteroid generated response on the effects of cadmium on photosynthetic machinery and active oxygen metabolism in two tomato cultivars (K-25 and Sarvodya). These tomato cultivars were subjected to graded cadmium levels in soil (0, 3, 6, 9 or 12 mg kg(-1) soil) with their foliage being sprayed with 0 or 10(-8) M of 28-homobrassinolide/24-epibrassinolide (HBL/EBL) at 59 d stage. The results suggested that photosynthetic parameters, leaf water potential and activity of several enzymes (nitrate reductase and carbonic anhydrase) decreased significantly in both the cultivars, to a lesser extent in K-25 than Sarvodya with the increasing levels of cadmium in the soil. However, the activity of antioxidant enzymes and proline content increased in response to metal treatment as well as the application of brassinosteroids (HBL/EBL). Overall, exogenous application of brassinosteroids improved the activity of photosynthetic machinery and that of antioxidant defense system in both the cultivars, and also nullified the damaging effect of metal on these parameters.
authors.affiliation: Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh 202 002, UP, India.
authors.forename: Syed Aiman
authors.initials: SA
authors.lastname: Hasan
authors.forename: Shamsul
authors.initials: S
authors.lastname: Hayat
authors.forename: Aqil
authors.initials: A
authors.lastname: Ahmad
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D060406:Brassinosteroids / Q000494:pharmacology; D002104:Cadmium / Q000633:toxicity*; D002778:Cholestanones / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects*; D012989:Soil Pollutants / Q000633:toxicity*; D013260:Steroids, Heterocyclic / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D060406:Brassinosteroids; D002778:Cholestanones; D012989:Soil Pollutants; D013260:Steroids, Heterocyclic; D002104:Cadmium; C070163:homobrassinolide; C023623:brassinolide