Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 25, 2004
Publication Date: September 1, 2004
Citation: Altenbach, S.B., Kothari, K.M. 2004. Transcript profiles of genes expressed in endosperm tissue are altered by high temperatures during wheat grain development. Journal of Cereal Science. Vol.40 No.2 Interpretive Summary: The timing of expression for genes involved in different cellular processes was examined in developing grains from wheat plants grown under either moderate or high temperature conditions. Genes expressed at early, middle and late stages of grain development under each temperature treatment were identified and the timing of gene expression was compared to the timing of physiological events during grain development. Genes expressed at similar developmental stages under the two temperature regimens were identified. These genes might serve as markers for grain development. The timing of expression for a number of other genes was shifted under high temperatures in a manner that was not consistent with developmental events. These genes may be involved in responses to high temperature that are distinct from effects on the timing of developmental processes. These experiments are a first step in understanding programs of gene expression during grain development and the effects of high temperatures on those programs.
Technical Abstract: Timing of transcript accumulation for genes involved in a variety of cellular processes was assessed by RT-PCR in endosperm from developing wheat grains grown under moderate (24/17oC day/night) and high (37/28oC day/night) temperature regimens. Under moderate temperatures, transcripts for proteins with storage functions were present at the five time points examined between 7 and 34 DPA, while transcripts for proteins involved in signal transduction, protein synthesis and metabolism were most abundant from 7 to 20 DPA. Transcripts for proteins that play roles in defense were present from 14 DPA, about the time that starch accumulation commenced, to 34 DPA. High temperatures advanced and compressed the timing of transcript accumulation during grain development. Comparisons of transcript profiles with the timing of key events in grain development identified genes whose transcripts were accumulated at equivalent stages under the two temperature regimens and might serve as markers for grain development. These comparisons also revealed a number of genes with transcript profiles that were shifted under high temperatures in a manner that was not consistent with developmental events. These genes may be involved in responses to high temperature that are distinct from effects on the timing of developmental processes.