Australian Centre for Plant Functional Genomics and the University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia.
Plant Cell Environ. 2013 Mar;36(3):553-68. doi: 10.1111/j.1365-3040.2012.02595.x. Epub 2012 Sep 10.
Salinity is a major abiotic stress which affects crop plants around the world, resulting in substantial loss of yield and millions of dollars of lost revenue. High levels of Na(+) in shoot tissue have many adverse effects and, crucially, yield in cereals is commonly inversely proportional to the extent of shoot Na(+) accumulation. We therefore need to identify genes, resistant plant cultivars and cellular processes that are involved in salinity tolerance, with the goal of introducing these factors into commercially available crops. Through the use of an Arabidopsis thaliana mapping population, we have identified a highly significant quantitative trait locus (QTL) linked to Na(+) exclusion. Fine mapping of this QTL identified a protein kinase (AtCIPK16), related to AtSOS2, that was significantly up-regulated under salt stress. Greater Na(+) exclusion was associated with significantly higher root expression of AtCIPK16, which is due to differences in the gene's promoter. Constitutive overexpression of the gene in Arabidopsis leads to plants with significant reduction in shoot Na(+) and greater salinity tolerance. amiRNA knock-downs of AtCIPK16 in Arabidopsis show a negative correlation between the expression levels of the gene and the amount of shoot Na(+) . Transgenic barley lines overexpressing AtCIPK16 show increased salinity tolerance.
盐度是一种主要的非生物胁迫，影响着世界各地的作物，导致产量大幅下降和数百万美元的收入损失。茎组织中高浓度的 Na(+) 有许多不利影响，而且，谷物的产量通常与茎部 Na(+) 积累的程度成反比。因此，我们需要确定参与耐盐性的基因、抗性植物品种和细胞过程，目标是将这些因素引入商业上可用的作物中。通过使用拟南芥作图群体，我们已经确定了一个与 Na(+) 排斥相关的高度显著的数量性状位点 (QTL)。对这个 QTL 的精细定位确定了一种与 AtSOS2 相关的蛋白激酶（AtCIPK16），它在盐胁迫下显著上调。Na(+) 排斥的增加与根中 AtCIPK16 的表达显著增加有关，这是由于基因启动子的差异。在拟南芥中组成型过表达该基因会导致植物的茎部 Na(+) 显著减少和耐盐性增强。在拟南芥中 amiRNA 敲低 AtCIPK16 显示基因表达水平与茎部 Na(+) 含量之间存在负相关。过表达 AtCIPK16 的转基因大麦品系显示出增强的耐盐性。
