Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2015
Publication Date: 4/7/2015
Citation: Burke, J.J., Chen, J. 2015. Enhancement of reproductive heat tolerance in plants. PLoS One. 10(4):1-23.
Interpretive Summary: Yield reductions occur annually because of high temperatures during the reproductive phase of crop growth. Pollen has been reported to be extremely sensitive to even a few degrees above the optimum. This study introduced a gene for heat-tolerance into pollen and evaluated associated changes in pollen health and yield enhancements. Introduction of the heat shock protein 101 into tobacco and cotton pollen improved yields and pollen health during exposure to elevated temperatures. These findings suggest that we can introduce heat-tolerance into pollen and improve yields under stress conditions.
Technical Abstract: The current study investigated the enhancement of plant reproductive heat tolerance through the use of a gene encoding the Arabidopsis thaliana heat shock protein 101 (AtHSP101) not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The Arabidopsis thaliana heat shock protein 101 was placed under the control of the constitutive ocs/mas ‘superpromoter’, incorporated into an expression vector and transferred into cotton hypocotyls and tobacco leaf disc cells via Agrobacterium. Enhanced heat tolerance of tobacco pollen from the transgenic plants has been identified via in vitro pollen germination studies. Both primary transformants and homozygous transgenic individuals from a segregating F3 population derived from a backcross with non-transgenic SR1 tobacco exhibited enhanced pollen germination and greater pollen tube lengths following a heat exposure. AtHSP101 expressing Coker 312 cotton pollen also exhibited enhance heat tolerance in in vitro pollen germination assays. Increased boll set and greater seed numbers also were observed in transgenic cotton exposed to elevated day and night temperatures in both greenhouse and field studies.