KSEF RDE: Posttranscriptional Control of Responses of Plants to Elevated Temperatures

Heat stress is a key factor that limits crop production and yield world-wide. Such stress may be manifest in concert with drought stress, since elevated temperatures often lead to decreased supply and/or availability of water in agriculture. However, elevated temperatures can impair crop growth, development, and yield even in situations where water is plentiful. For these reasons, high temperatures have limited crop productivity for as long as crops have been grown outside of their original geographic locales, and these limitations are likely to become more dramatic as global temperatures rise. Accordingly, a better understanding of the means by which plants respond to and overcome the stresses imposed by elevated temperatures is a going concern and a desirable goal for plant biotechnology research. As part of ongoing research in the PI’s laboratory, it has been determined that alterations in the expression of a gene encoding an Arabidopsis polyadenylation factor subunit (AtCPSF30) can alter the responses of the plant to elevated temperatures. Specifically, plants with altered expression of AtCPSF30 are more tolerant of experimental heat stress treatments, and unstressed plants have elevated expression of genes often associated with responses to, and survival of, heat stress. These characteristics are reminiscent of plants that have been primed to withstand severe heat stress. Based on these studies, it is hypothesized that an important aspect of priming in plants a significant shift of poly(A) site choice, and that such shifts are mediated by AtCPSF30. To test this hypothesis, the ability of CPSF30 mutants to exhibit priming will be tested, and a high throughput sequencing approach will be used to study poly(A) site choice genome-wide in heat-stressed Arabidopsis plants. It is expected that CPSF30-dependent genes that are important for priming will be identified; these will help to define a novel network of posttranscriptionally-regulated genes important for the responses of plants to heat stress. Such knowledge will facilitate the development of transgenic crop varieties with improved performance in warmer climates.