Working group session:
Germplasm and Genetic Stocks
Presentation type:
oral
Authors:
Zhang, Hong; Sun, Li; Payton, Paxton; Burke, John ; Kuppu, Sundaram
Presenter:
Zhang, Hong
Correspondent:
Zhang, Hong
Abstract:
Drought is the major limiting factor for cotton production in the US. Climate change will likely make cotton production even more difficult. Making cotton resistant to drought in order to maintain sustainable fiber production in arid and semiarid areas is extremely important for Southwestern USA. Among the efforts to achieve such a goal, up regulating cytokinin production by ectopically expressing the IPT gene to delay the drought induced senescence appears to be the most promising. Despite consistent data showing improved tolerance to drought by doing so, we noticed that the timing of the water deficit stress might be very important to this trait. We analyzed IPT-transgenic cotton lines in greenhouse for two rounds to check the impact of drought stress timing on their final yields in comparing to wild-type plants and segregated non-transgenic lines. Our data shows that IPT-transgenic plants out-performed non-transgenic controls dramatically only when water deficit stress took place earlier in their growth period. If the water-deficit stress was applied 55 days after germination, no significant differences were observed in the final yields between IPT-transgenic plants and non-transgenic controls. These results indicate that the IPT gene driven by the SARK promoter is more effective during early stages of cotton growth and development in regarding increasing final yield after drought treatment.