Tan Meixia, Yang Yang, Chen Zhe, Gong Xiangyuan, Ma Fangfang, Duan Ming, Wang Lidong, Han Yuanhuai
College of Agriculture, Shanxi Agricultural University, Taiyuan 030031, China.
Experimental Teaching Center, Shanxi Agricultural University, Taiyuan 030031, China.
Plants (Basel). 2025 Aug 14;14(16):2535. doi: 10.3390/plants14162535.
Efficient and fast water uptake by seeds, facilitated by optimal soil moisture, plays a critical role in timely germination and early seedling vigor for foxtail millet production in arid and semi-arid regions. The husk, as a unique structure through which the seed contacts the soil, plays an important role in water uptake and germination. Many foxtail millet germplasm accessions have papillae on the epidermis of their husks, yet the role of this trait in water uptake and germination, as well as the genetic basis and regulatory mechanism related to this trait, remain unknown. In this study, we demonstrated that the water uptake by the seeds from accessions with papillae was significantly higher than that of accessions without papillae two hours and four hours after sowing during a 10 h experiment, resulting in faster germination. Analysis of segregating ratios from two F2 populations derived from crossing between accessions with and without papillae indicated that husk papilla density was of monogenic dominance. Bulked Segregant Analysis Sequencing (BSA-Seq) showed that candidate regions on chromosome 5 were significantly associated with husk papilla density. The mapped region overlapped by the two BSA populations for papilla density included 72 genes. In combination with the expression profiles of these genes, five candidate genes were identified, encoding aquaporins, fructose transporter, and glycoside hydrolase. This study elucidated the role of husk papillae in enhancing water uptake and germination in foxtail millet, provided genetic insights into the trait, and laid the foundation for further study on the mechanism of husk papilla differentiation.
在干旱和半干旱地区的谷子生产中，种子在最佳土壤湿度的促进下高效快速地吸收水分，这对及时发芽和早期幼苗活力起着关键作用。谷壳作为种子与土壤接触的独特结构，在水分吸收和发芽过程中发挥着重要作用。许多谷子种质资源的谷壳表皮有乳头状突起，然而该性状在水分吸收和发芽中的作用，以及与该性状相关的遗传基础和调控机制尚不清楚。在本研究中，我们证明在10小时的实验中，播种后两小时和四小时，有乳头状突起的种质资源的种子吸水量显著高于没有乳头状突起的种质资源，从而发芽更快。对有和没有乳头状突起的种质资源杂交产生的两个F2群体的分离比例分析表明，谷壳乳头状突起密度呈单基因显性。混合分组分析法测序（BSA-Seq）显示，5号染色体上的候选区域与谷壳乳头状突起密度显著相关。两个BSA群体的乳头状突起密度定位区域重叠，包含72个基因。结合这些基因的表达谱，鉴定出五个候选基因，分别编码水通道蛋白（aquaporins）、果糖转运蛋白（fructose transporter）和糖苷水解酶（glycoside hydrolase）。本研究阐明了谷壳乳头状突起在增强谷子水分吸收和发芽中的作用，提供了该性状的遗传见解，并为进一步研究谷壳乳头状突起分化机制奠定了基础。
