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Brassinolide Application Improves the Drought Tolerance in Maize Through Modulation of Enzymatic Antioxidants and Leaf Gas Exchange
Author(s) -
Anjum S. A.,
Wang L. C.,
Farooq M.,
Hussain M.,
Xue L. L.,
Zou C. M.
Publication year - 2011
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.2010.00459.x
Subject(s) - brassinolide , transpiration , water use efficiency , stomatal conductance , seedling , photosynthesis , drought tolerance , chlorophyll , agronomy , biomass (ecology) , proline , abiotic component , biology , chemistry , horticulture , botany , plant growth , biochemistry , paleontology , amino acid
Brassinolides (BRs) are naturally occurring substances, which modulate plant growth and development events and have been known to improve the crop tolerance to abiotic stresses. In this study, possible role of exogenously applied brassinolide (BR) in alleviating the detrimental effects of drought in maize was evaluated in a rain‐protected wire‐house. Maize was subjected to drought at the start of tasseling for 6 days by withholding water application followed by foliar spray of BR (0.1 mg l −1 ) to assess the changes in growth, gas exchange, chlorophyll contents, protein, relative leaf water contents (RLWC), proline, malonialdehyde (MDA) and enzymatic antioxidants. Drought substantially reduced the maize growth in terms of plant height, leaf area and plant biomass. Moreover, substantial decrease in gas exchange attributes (net photosynthetic rate (A), transpiration rate (E), stomatal conductance (g s ), water use efficiency (WUE), instantaneous water use efficiency (WUEi) and intercellular CO 2 (C i ) was also recorded. However, exogenous application of BR remarkably improved the gas exchange attributes, plant height, leaf area, cobs per plant, seedling dry weight both under drought and well‐watered conditions. BR‐induced promotion in growth and physiological and metabolic activities were mediated through increased protein synthesis enabling maintenance of tissue water potential and activities of antioxidant enzymes lowering the lipid peroxidation under drought.