Table_4_Salt-Enhanced Reproductive Development of Suaeda salsa L. Coincided With Ion Transporter Gene Upregulation in Flowers and Increased Pollen K+ Content.docx

Halophytes are adapted to saline environments and demonstrate optimal reproductive growth under high salinity. To gain insight into the salt tolerance mechanism and effects of salinity in the halophyte Suaeda salsa, the number of flowers and seeds, seed size, anther development, ion content, and flower transcript profiles, as well as the relative expression levels of genes involved in ion transport, were analyzed in S. salsa plants treated with 0 or 200 mM NaCl. The seed size, flower number, seed number per leaf axil, and anther fertility were all significantly increased by 200 mM NaCl treatment. The Na+ and Cl− contents in the leaves, stems, and pollen of NaCl-treated plants were all markedly higher, and the K+ content in the leaves and stems was significantly lower, than those in untreated control plants. By contrast, the K+ content in pollen grains did not decrease, but rather increased, upon NaCl treatment. Genes related to Na+, K+ and, Cl− transport, such as SOS1, KEA, AKT1, NHX1, and CHX, showed increased expression in the flowers of NaCl-treated plants. These results suggest that ionic homeostasis in reproductive organs, especially in pollen grains under salt-treated conditions, involves increased expression of ion transport-related genes.

卤生植物适应于盐碱环境，并在高盐浓度下展现出最佳繁殖生长。为深入探究卤生植物（Suaeda salsa）的耐盐机制及盐分对其的影响，本研究分析了经0或200 mM NaCl处理的S. salsa植株的花朵数量与种子数、种子尺寸、花药发育、离子含量以及花转录组特征，以及参与离子运输相关基因的相对表达水平。200 mM NaCl处理显著增加了种子尺寸、花朵数量、每叶腋的种子数以及花药育性。NaCl处理植株的叶片、茎和花粉中的Na+和Cl-含量均显著高于未处理对照植株，而叶片和茎中的K+含量则显著降低。然而，经NaCl处理后，花粉粒中的K+含量并未降低，反而有所增加。与Na+、K+和Cl-运输相关的基因，如SOS1、KEA、AKT1、NHX1和CHX，在NaCl处理植株的花朵中表现出表达水平的升高。这些结果表明，在盐处理条件下，生殖器官中的离子稳态，尤其是花粉粒，涉及离子运输相关基因表达水平的增加。