Recent advances in research on drought-induced proteins and the related genes in wheat (Triticum aestivu L.)

Under drought stress, target genes in wheat (Triticum aestivum L.) need to be activated and expressed to produce drought-induced proteins, enabling plants to actively adapt to drought, and to maintain survival and yield formation. Drought-induced proteins can be divided into two categories according to their function, one are the proteins that prevent cell dehydration with direct protective function such as LEA proteins and metabolic enzymes, etc., and the second are the transcription factors and protein kinases that are involved in cell signal transduction or gene expression regulation with indirect protective function. This paper summarizes recent advances in drought-induced proteins and their related geres in wheat, including the different responses and common features among wheat varieties, stress levels and developmental stages. Also, the different responses to ABA and Ca super(2+), the major drought signals, the biological characteristics and the major functions of the newly-discovered drought-induced proteins and the related genes are discussed. In research on drought-induced proteins, the methods and objectives have shifted from revealing the differences in the expression of protein bands using the one-way electrophoresis-based technique in the past, to currently exploring the coupled structure and function of drought-induced proteins in the proteome with two-dimensional electrophoresis technology. To date, the hot issues of research have focused on the relationship of drought-induced proteins with signal transduction, material transportation, reactive oxygen groups, carbon metabolism and nitrogen metabolism. There are two predominant categories of genes, regulatory genes and functional genes, which are related to drought-induced proteins. The research on functional genes is concentrated on the LEA protein genes, D-responsive protein genes, the gene encoding photosystem II polypeptides and the synthase genes of osmotic regulatory substances. The research on regulatory genes is focused on gene transcription factors and the genes related to protein kinases and their roles. According to the latest report (2010), the world's first wheat genome draft has been completed, which has laid the foundation for drawing a complete map of the wheat genome. This important progress will help to reveal the physiological function and ultrastructure of drought-induced proteins in wheat. The experimental material used in this genome sequence mapping is a wheat variety