Transcriptome Changes for Arabidopsis in Response to Salt, Osmotic, and Cold Stress,

Abstract

To identify genes of potential importance to cold, salt, and drought tolerance, global expression profiling was performed on Arabidopsis plants subjected to stress treatments of 4°C, 100 mm NaCl, or 200 mm mannitol, respectively. RNA samples were collected separately from leaves and roots after 3-and 27-h stress treatments. Profiling was conducted with a GeneChip microarray with probe sets for approximately 8,100 genes. Combined results from all three stresses identified 2,409 genes with a greater than 2-fold change over control. This suggests that about 30% of the transcriptome is sensitive to regulation by common stress conditions. The majority of changes were stimulus specific. At the 3-h time point, less than 5% (118 genes) of the changes were observed as shared by all three stress responses. By 27 h, the number of shared responses was reduced more than 10-fold (Ͻ 0.5%), consistent with a progression toward more stimulus-specific responses. Roots and leaves displayed very different changes. For example, less than 14% of the cold-specific changes were shared between root and leaves at both 3 and 27 h. The gene with the largest induction under all three stress treatments was At5g52310 (LTI/COR78), with induction levels in roots greater than 250-fold for cold, 40-fold for mannitol, and 57-fold for NaCl. A stress response was observed for 306 (68%) of the known circadian controlled genes, supporting the hypothesis that an important function of the circadian clock is to "anticipate" predictable stresses such as cold nights. Although these results identify hundreds of potentially important transcriptome changes, the biochemical functions of many stress-regulated genes remain unknown.Plants have a remarkable ability to cope with highly variable environmental stresses, including cold, drought, and soils with changing salt and nutrient concentrations (i.e. abiotic stress). Nevertheless, these stresses together represent the primary cause of crop loss worldwide (Boyer, 1982), reducing average yields for most major crop plants by more than 50% (Bray et al., 2000). In contrast, the estimated yield loss caused by pathogens is typically around 10% to 20%.Significant progress has been made to understand and manipulate abiotic stress responses (for reviews, see Shinozaki and Yamaguchi-Shinozaki, 1996;Bohnert and Sheveleva, 1998;Smirnoff, 1998;Blumwald, 2000;Bray et al., 2000;Cushman and Bohnert, 2000;Hasegawa et al., 2000;Knight, 2000;Schroeder et al., 2001;Serrano and Rodriguez-Navarro, 2001;Thomashow, 2001;Zhu, 2001bZhu, , 2001a. Three important themes have emerged.First, the initiation of most stress treatments correlates with a cytosolic calcium release, in some cases with stimulus-specific patterns of oscillation (Allen et al., 2000;Knight, 2000;Posas et al., 2000). Second, stimulus-specific changes in gene expression are often observed alongside a set of shared stress responses. For example, in a survey of 1,300 Arabidopsis genes, the majority of cold and drought stressregulated genes were observed as a shared stress ...

The mutual responses of higher plants to environment: Physiological and microbiological aspects

“…Besides, much data sets are from under condition of one type of stresses. It is a fact that plants always confront more than two kinds of individual environmental stresses or their combination simultaneously in field [68,72,73]. Although drawing plant gene regulatory network system with great details and complete pathways is impossible currently, the basic draft for this blueprint has been summarized in the recent publications [69,101,102,106,120,121,126,147].…”

Genetic approaches towards overcoming water deficit in plants - special emphasis on LEAs

“…Transcript profiling using gene chips or longoligonucleotide array slides, provided important insights into the dynamics of the transcriptional changes that accompany abiotic stress treatments. Several contributions have emerged on changes in transcript profiles under cold, drought, and high-salinity conditions, mainly in A. thaliana and rice, and other species, focusing on stress responses (Kreps et al, 2002;Rabbani et al, 2003;Buchannan et al, 2005). A new avenue has been opened by the detection of regulatory systems that depend on small non-coding RNAs in plants.…”

Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at tillering stage

“…Drought is a complex physical-chemical process, in which many biological macromolecules and small molecules are involved, such as nucleic acids (DNA, RNA, microRNA), proteins, carbohydrates, lipids, hormones, ions, free radicals, mineral elements [3,8,12,13,18,20,22,26,31,43,49,50,55,65]. In addition, drought is also related to salt stress, cold stress, high temperature stress, acid stress, alkaline stress, pathological reactions, senescence, growth, development, cell cycle, UV-B damage, wounding, embryogenesis, flowering, signal transduction and so on [16,17,[26][27][28]36,37,[44][45][46][47][52][53][54]62]. Therefore, drought is connected with almost all aspects of biology.…”

“…These results also imply that systemical, deeper, and comprehensive understanding of physiological mechanism of crops under drought stresses is not enough to manipulate the physiological regulatory mechanism and take advantage of full this potential for productivity, Whose study is the bridge between molecular machinery of drought and anti-drought agriculture, because the performance of genetic potential of crops is expressed by physiological realization in fields [36,53,56,62,65]. Towards this aim, many promising methodologies emerge, but they should also be linked with field practice [6,9,11,14,25,42,54,57].…”