Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
Department of Biology, Chiba University, Chiba 263-8522, Japan.
Nat Plants. 2017 May 26;3:17072. doi: 10.1038/nplants.2017.72.
Osmotic stress caused by drought, salt or cold decreases plant fitness. Acquired stress tolerance defines the ability of plants to withstand stress following an initial exposure. We found previously that acquired osmotolerance after salt stress is widespread among Arabidopsis thaliana accessions. Here, we identify ACQOS as the locus responsible for ACQUIRED OSMOTOLERANCE. Of its five haplotypes, only plants carrying group 1 ACQOS are impaired in acquired osmotolerance. ACQOS is identical to VICTR, encoding a nucleotide-binding leucine-rich repeat (NLR) protein. In the absence of osmotic stress, group 1 ACQOS contributes to bacterial resistance. In its presence, ACQOS causes detrimental autoimmunity, thereby reducing osmotolerance. Analysis of natural variation at the ACQOS locus suggests that functional and non-functional ACQOS alleles are being maintained due to a trade-off between biotic and abiotic stress adaptation. Thus, polymorphism in certain plant NLR genes might be influenced by competing environmental stresses.
干旱、盐或寒冷引起的渗透胁迫会降低植物的适应能力。获得性胁迫耐受定义了植物在初次暴露于胁迫后耐受胁迫的能力。我们之前发现，盐胁迫后获得的渗透耐受性在拟南芥中广泛存在。在这里，我们将 ACQOS 鉴定为负责获得性渗透耐受性的基因座。在其五个单倍型中，只有携带第 1 组 ACQOS 的植物在获得性渗透耐受性方面受损。ACQOS 与 VICTR 相同，后者编码核苷酸结合亮氨酸丰富重复（NLR）蛋白。在没有渗透胁迫的情况下，第 1 组 ACQOS 有助于抵抗细菌。在存在渗透胁迫的情况下，ACQOS 会导致有害的自身免疫，从而降低渗透耐受性。对 ACQOS 基因座的自然变异分析表明，由于生物和非生物胁迫适应之间的权衡，功能性和非功能性 ACQOS 等位基因得以维持。因此，某些植物 NLR 基因的多态性可能受到竞争环境胁迫的影响。
