Enhancement of Reproductive Heat Tolerance in Plants

Abstract

Comparison of average crop yields with reported record yields has shown that major crops exhibit annual average yields three- to seven-fold lower than record yields because of unfavorable environments. The current study investigated the enhancement of pollen heat tolerance through expressing an Arabidopsis thaliana heat shock protein 101 (AtHSP101) that is not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The AtHSP101 construct under the control of the constitutive ocs/mas ‘superpromoter’ was transformed into cotton Coker 312 and tobacco SRI lines via Agrobacterium mediated transformation. Thermotolerance of pollen was evaluated by in vitro pollen germination studies. Comparing with those of wild type and transgenic null lines, pollen from AtHSP101 transgenic tobacco and cotton lines exhibited significantly higher germination rate and much greater pollen tube elongation under elevated temperatures or after a heat exposure. In addition, significant increases in boll set and seed numbers were also observed in transgenic cotton lines exposed to elevated day and night temperatures in both greenhouse and field studies. The results of this study suggest that enhancing heat tolerance of reproductive tissues in plant holds promise in the development of crops with improved yield production and yield sustainability in unfavorable environments.

Overexpression of receptor-like kinase ERECTA improves thermotolerance in rice and tomato

“…Our findings indicate that overexpression of ER is likely superior to using HSPs to improve thermotolerance 9,14 . Plants engineered to produce HSP101 have not been tested in multiple locations or through several growing seasons and HSP overexpression in model plants has been associated with growth penalties under nonstress conditions 34 .…”

“…Overexpression of HSP101 increased tolerance to heat shock or prolonged heat stress in transgenic Arabidopsis, tobacco and cotton 9,14 , although transgenic cotton produced fewer bolls and seeds than control cotton plants under normal growth conditions 14 .…”

“…Plants respond to temperature changes by reprogramming their growth and development [4][5][6][7][8] , and progress has been made towards genetic modification of plants to increase their tolerance to heat stress. However, these studies have mainly been restricted to the model plant Arabidopsis [9][10][11][12][13][14] . Many studies have shown that expression of heat shock proteins (HSPs) can improve the tolerance of transgenic plants to heat shock (short exposure to high temperatures) 15 .…”

Pollen Development at High Temperature: From Acclimation to Collapse

“…Here, we discuss the current understanding of heat acclimation responses and heat injury during microspore development. Thermotolerance mechanisms of mature and germinating pollen as well as vegetative tissues have been discussed elsewhere (Mittler et al, 2012;Bokszczanin et al, 2013;Tunc-Ozdemir et al, 2013;Burke and Chen, 2015).…”

Vulnerability of Southern Plains agriculture to climate change

“…Ongoing breeding programs for crops need to increase drought, heat, and flooding tolerance in order to account for changing hydrologic and temperature dynamics (Burke and Chen 2015;Wang et al 2014;Emendack et al 2014). New crop species require extensive agronomic research and development of production and marketing infrastructure within a region.…”