Patterns of gene expression in wheat grains during a typical growing season in the Great Plains

Abstract

We are using microarrays to investigate the transcriptional response of wheat grains to heat stress during growth on the Great Plains. Increasing temperatures not only affect grain set but also the rate and duration of grain filling. Shortening of the duration of the grain filling period is mainly responsible for reduced kernel weight when temperatures increase after grain set is completed. To improve our understanding of the wheat plant¿s response to heat we are correlating changes in RNA expression patterns in relation to the climate in a field near Manhattan, Kansas. Temperatures were recorded at ear level as well as at 20 cm soil depth. MRNA from grains harvested on a daily basis were hybridised against two microarrays each containing about 8000 cDNAs from several wheat libraries. We present gene expression patterns during the development of grains from watery ripe to hard caryopses (Zadok 71 to 93). The potential and the limitations of this experiment will be discussed. To support this approach an additional set of plants will be analysed. They will be grown in growth chambers under controlled conditions to compare expression patterns of heat-treated plants with untreated plants.