Pariasca-Tanaka Juan, Baertschi Cedric, Wissuwa Matthias
Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Japan.
Front Plant Sci. 2020 Jan 15;10:1668. doi: 10.3389/fpls.2019.01668. eCollection 2019.
Sulfur (S) is an essential nutrient for plant growth and development; however, S supply for crop production is decreasing due to reduced inputs from atmospheric deposition and reduced application of S-containing fertilizers. Sulfur deficiency in soil is therefore becoming a widespread cause of reduced grain yield and quality in rice ( L). We therefore assessed the genotypic variation for tolerance to S deficiency in rice and identified loci associated with improved tolerance. Plants were grown in nutrient solution with either low (0.01 mM) or high (1.0 mM) supply of S. Plants grown under low-S treatment showed a reduction in total biomass, mainly due to a marked reduction in shoot biomass, while root biomass and root-to-shoot ratio increased, relative to plants under high-S treatment. Genome-wide association studies (GWAS) identified loci associated with root length ( and ), and root () or total dry matter ( and ). Candidate genes identified at associated loci coded for enzymes involved in secondary S metabolic pathways (sulfotransferases), wherein the sulfated compounds play several roles in plant responses to abiotic stress; cell wall metabolism including wall loosening and modification (carbohydrate hydrolases: beta-glucosidase and beta-gluconase) important for root growth; and cell detoxification (glutathione S-transferase). This study confirmed the existence of genetic variation conferring tolerance to S deficiency among traditional aus rice varieties. The advantageous haplotypes identified could be exploited through marker assisted breeding to improve tolerance to S-deficiency in modern cultivars in order to achieve sustainable crop production and food security.
硫（S）是植物生长发育所必需的营养元素；然而，由于大气沉降输入减少和含硫肥料施用量降低，用于作物生产的硫供应正在减少。因此，土壤缺硫正成为水稻减产和品质下降的一个普遍原因。我们因此评估了水稻对缺硫耐受性的基因型变异，并鉴定了与耐受性提高相关的基因座。将植株种植在硫供应低（0.01 mM）或高（1.0 mM）的营养液中。与高硫处理的植株相比，低硫处理下生长的植株总生物量减少，主要是由于地上部生物量显著降低，而根生物量和根冠比增加。全基因组关联研究（GWAS）鉴定了与根长（和）、根（）或总干物质（和）相关的基因座。在相关基因座鉴定出的候选基因编码参与硫次生代谢途径的酶（磺基转移酶），其中硫酸化化合物在植物对非生物胁迫的反应中发挥多种作用；细胞壁代谢包括对根系生长重要的细胞壁松弛和修饰（碳水化合物水解酶：β-葡萄糖苷酶和β-葡萄糖酸酶）；以及细胞解毒（谷胱甘肽S-转移酶）。本研究证实了传统奥氏稻品种中存在赋予缺硫耐受性的遗传变异。所鉴定的有利单倍型可通过标记辅助育种加以利用，以提高现代品种对缺硫的耐受性，从而实现可持续作物生产和粮食安全。
