Ai Xin, Wang Shiyu, Dai Runze, Ma Xinlei, Li Chenghua, Zhong Chao, Wang Jing, Liu Xibo, Zhao Xinhua, Zhang He, Yu Haiqiu
College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, 110161, China.
College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, 110161, China; Liaoning Agriculture Vocational and Technical College, Yingkou, Liaoning, 115009, China.
Plant Physiol Biochem. 2025 Feb;219:109336. doi: 10.1016/j.plaphy.2024.109336. Epub 2024 Nov 28.
Soil water deficit is a key environmental factor limiting peanut yield and quality, which can occur at any growth stage of peanut. But the exact mechanism of soil water deficit affecting the formation of peanut yield and quality remains unclear. In this study, the seed development, yield components, oil accumulation and fatty acid composition of common (HY25; FH18) and high oleic acid varieties (KN71; HY52) under soil water deficit throughout the growth period were investigated. It was found that the decrease of pod number and 100-pod weight per plant was the main factor leading to the reduction in peanut yield under soil water deficit. The number of oil bodies, maximum oil accumulation rate and oil content were significantly reduced, especially in drought-sensitive peanut varieties. The down-regulation of enzyme activities on the Kennedy pathway was the main factor hindering oil synthesis. Peanut varieties with lower levels of FAD2 transcripts might more sensitive to drought stress in terms of fatty acid metabolism. Under soil water deficiency, high oleic acid peanut oleate synthase activity was reduced, oleic acid metabolizing enzyme activity was elevated, which lead to decreased oleic acid content and the ratio of oleic acid to linoleic acid (O/L), and impaired lipid quality. Among them, the lipid quality of HY52 was most severely compromised. In contrast, the common varieties exhibited opposite enzyme activity patterns, with increases in oleic acid content and O/L, and improved lipid quality. This study elucidated the response mechanism of peanut grain development and oil metabolism to soil water deficit, which can provide theoretical basis and technical support for realizing high quality and stable yield of peanut under adversity.
土壤水分亏缺是限制花生产量和品质的关键环境因素，在花生的任何生长阶段都可能发生。但土壤水分亏缺影响花生产量和品质形成的确切机制尚不清楚。本研究调查了普通品种（HY25；FH18）和高油酸品种（KN71；HY52）在整个生育期土壤水分亏缺条件下的种子发育、产量构成因素、油脂积累和脂肪酸组成。结果发现，土壤水分亏缺条件下，单株荚果数和百果重下降是导致花生产量降低的主要因素。油体数量、最大油脂积累速率和含油率显著降低，尤其是对干旱敏感的花生品种。肯尼迪途径中酶活性的下调是阻碍油脂合成的主要因素。FAD2转录本水平较低的花生品种在脂肪酸代谢方面可能对干旱胁迫更敏感。在土壤水分亏缺条件下，高油酸花生油酸合成酶活性降低，油酸代谢酶活性升高，导致油酸含量和油酸与亚油酸比值（O/L）下降，油脂品质受损。其中，HY52的油脂品质受损最严重。相反，普通品种表现出相反的酶活性模式，油酸含量和O/L增加，油脂品质改善。本研究阐明了花生籽粒发育和油脂代谢对土壤水分亏缺的响应机制，可为实现逆境条件下花生的优质稳产提供理论依据和技术支持。
