Gong Qingqiu, Li Pinghua, Ma Shisong, Indu Rupassara S, Bohnert Hans J
Department of Plant Biology, University of Illinois at Urbana-Champaign, 61801, USA.
Plant J. 2005 Dec;44(5):826-39. doi: 10.1111/j.1365-313X.2005.02587.x.
In stark contrast to Arabidopsis, a related species, Thellungiella halophila (Thellungiella salsuginea; salt cress), displays extreme tolerance to high salinity, low humidity and freezing. High nucleotide sequence identity permits the use of tools developed for Arabidopsis for Thellungiella transcript profiling, for which a microarray platform with >25,000 DNA elements (70-mer oligonucleotides) was used. Microarray transcript profiling and intensity analysis, quantitative RT-PCR, and metabolite profiles define genes and pathways that showed shared and divergent responses to salinity stress in the two species. Shared responses are exemplified by 40% of the regulated genes functioning in confining ribosomal functions, photosynthesis and cell growth, as well as activating osmolyte production, transport activities and abscisic acid-dependent pathways. An additional 60% of regulated genes distinguished Thellungiella from Arabidopsis. Analysis of the differences showed that Arabidopsis exhibited a global defense strategy that required bulk protein synthesis, while Thellungiella induced genes functioning in protein folding, post-translational modification and protein redistribution. At 150 mm NaCl, Thellungiella maintained unimpeded growth. Transcript intensity analyses and metabolite profiles supported the microarray results, pointing towards a stress-anticipatory preparedness in Thellungiella.
与近缘物种拟南芥形成鲜明对比的是，盐芥（盐生盐芥）对高盐度、低湿度和冷冻具有极强的耐受性。高核苷酸序列同一性使得可将为拟南芥开发的工具用于盐芥的转录谱分析，为此使用了一个具有超过25,000个DNA元件（70聚体寡核苷酸）的微阵列平台。微阵列转录谱分析和强度分析、定量逆转录-聚合酶链反应以及代谢物谱确定了在这两个物种中对盐胁迫表现出共同和不同反应的基因及途径。共同反应的例证是，40%受调控的基因在限制核糖体功能、光合作用和细胞生长以及激活渗透溶质产生、转运活性和脱落酸依赖性途径方面发挥作用。另外60%受调控的基因使盐芥有别于拟南芥。对这些差异的分析表明，拟南芥展现出一种需要大量蛋白质合成的整体防御策略，而盐芥诱导在蛋白质折叠、翻译后修饰和蛋白质重新分布方面发挥作用的基因。在150 mM NaCl条件下，盐芥保持生长不受阻碍。转录强度分析和代谢物谱支持了微阵列结果，表明盐芥具有应激预期准备状态。
