1. Differential regulation of the banana stress NAC family by individual and combined stresses of drought and heat in susceptible and resistant genotypes.
- Author
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Chaudhari, Rakesh Shashikant, Jangale, Bhavesh Liladhar, Azeez, Abdul, Krishna, Bal, Sane, Prafullachandra Vishnu, and Sane, Aniruddha Prafullachandra
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BANANAS , *STEPFAMILIES , *DROUGHT management , *TROPICAL fruit , *GENOTYPES , *DROUGHTS , *TROPICAL crops - Abstract
Banana, an important tropical fruit crop, often faces drought, heat and its combination during its growth, leading to decreased yields. The combined stresses caused 100% yield loss in Grand Nain (GN) as compared to only 46% in Hill Banana (HB). To understand the response of combined stresses, we studied the stress-responsive NAC gene sub-family under individual and combined drought/heat stresses under controlled and field conditions in the stress-sensitive GN (AAA genotype) and stress-tolerant HB (AAB genotype). Under drought, expression of most stress- NACs increased with progression of drought in either one or the other genotype with little overlap. Heat stress caused a continuous decline in expression of most genes in HB unlike in GN where many NACs were up-regulated although to a lesser scale than for drought. Combination of the two stresses elicited a very different response compared with individual stresses. GN responded strongly to the combined stress with up-regulation of most genes unlike that seen in drought. Surprisingly, NAC genes in HB did not respond much to the more severe combination of the stresses despite being up-regulated strongly by drought. The response of the NACs to combined field stress was similar to that under controlled conditions. Most of the stress- NACs were strongly up-regulated upon treatment with exogenous ABA within 30–60 min, the increase being more prominent in GN. The studies suggest that the B genome in the stress-tolerant HB may counter more drastic combined stresses without taking recourse to the expression of stress NACs. • Banana stress NACs are activated by drought, heat and their combination. • Individual stresses show very different expression than combined stresses. • Hill Banana is more sensitive to individual drought stress than Grand Nain. • HB NACs are suppressed by heat and unresponsive to combined stresses unlike GN. • The B genome may alter responses to bypass NACs and the ABA-dependent pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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