Xu Shanbin, Zheng Jie, Du Haoqiang, Du Xiaodong, Li Chong, Duan Yuxuan, Cai Yanan, Wang Jingguo, Liu Hualong, Yang Luomiao, Xin Wei, Jia Yan, Zou Detang, Zheng Hongliang
Key Laboratory of Germplasm Enhancement and Physiology & Ecology of Food Crop in Cold Region, Ministry of Education/College of Agriculture, Northeast Agricultural University, Harbin, China.
Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi, China.
Front Plant Sci. 2024 Nov 1;15:1462856. doi: 10.3389/fpls.2024.1462856. eCollection 2024.
Soil salinization is one of the significant factors limiting high crop yields and expansion of arable land, seriously affecting global agricultural production. Rice is an essential food crop throughout the world, and its seedlings are particularly susceptible to salt stress, which can directly affect the growth and development of rice and its final yield. We used the natural population as the material for genome-wide association study (GWAS) and the recombinant inbred line (RIL) population from CD (salt sensitive)/WD20342 (salt tolerant) hybridization as the material for linkage analysis.
The degree of salt tolerance was evaluated by using the relative root length (RRL), relative root number (RRN), relative root fresh weight (RRFW), and relative root dry weight (RRDW) as indicators. Fifteen and six major quantitative trait loci (QTLs) were identified by GWAS and linkage analysis, respectively. Meanwhile, the GWAS identified the lead SNP (Chr2_22340368), which was located within qRRL2 and qRRDW2 identified by linkage analysis. GWAS, combined with linkage analysis, selected a 196-kb overlapping region on chromosome 2, including 22 candidate genes. was discovered as the candidate gene involved in salt tolerance by haplotype analysis, qRT-PCR, and sequence analysis. The score of salinity toxicity (SST) and seedling survival rate (SSR) were determined for CRISPR/Cas9 mutants (CR-1 and CR-15) and wild-type (ZH11), respectively.
The phenotypic validation indicated that negatively regulated the salt tolerance at the seedling stage. This study provides resources for breeding Japonica rice to improve its response to salt stress.
土壤盐渍化是限制作物高产和耕地扩张的重要因素之一，严重影响全球农业生产。水稻是全球重要的粮食作物，其幼苗对盐胁迫尤为敏感，这会直接影响水稻的生长发育及其最终产量。我们以自然群体为材料进行全基因组关联研究（GWAS），并以CD（盐敏感）/WD20342（耐盐）杂交产生的重组自交系（RIL）群体为材料进行连锁分析。
以相对根长（RRL）、相对根数（RRN）、相对根鲜重（RRFW）和相对根干重（RRDW）为指标评估耐盐程度。通过GWAS和连锁分析分别鉴定出15个和6个主要数量性状位点（QTL）。同时，GWAS鉴定出先导单核苷酸多态性（SNP）（Chr2_22340368），其位于连锁分析鉴定出的qRRL2和qRRDW2内。GWAS结合连锁分析，在2号染色体上选择了一个196 kb的重叠区域，包括22个候选基因。通过单倍型分析、qRT-PCR和序列分析发现 是参与耐盐性的候选基因。分别测定了CRISPR/Cas9突变体（CR-1和CR-15）和野生型（ZH11）的盐毒性评分（SST）和幼苗存活率（SSR）。
表型验证表明， 在幼苗期负调控耐盐性。本研究为粳稻育种提供了资源，以提高其对盐胁迫的响应。
