Genes encoding HKT1-like Na⁺ transporters play a key role in the salinity tolerance mechanism in Arabidopsis and other plant species by retrieving Na⁺ from the xylem of different organs and tissues. In this study, we investigated the role of two HKT1;2 allelic variants in tomato salt tolerance in relation to vegetative growth and fruit yield in plants subjected to salt treatment in a commercial greenhouse under real production conditions. We used two near-isogenic lines (NILs), homozygous for either the Solanum lycopersicum (NIL17) or S. cheesmaniae (NIL14) allele, at HKT1;2 loci and their respective RNAi-Sl/ScHKT1;2 lines. The results obtained show that both ScHKT1;2- and SlHKT1;2-silenced lines display hypersensitivity to salinity associated with an altered leaf Na⁺/K⁺ ratio, thus confirming that HKT1;2 plays an important role in Na⁺ homeostasis and salinity tolerance in tomato. Both silenced lines also showed Na⁺ over-accumulation and a slight, but significant, reduction in K⁺ content in the flower tissues of salt-treated plants and consequently a higher Na⁺/K⁺ ratio as compared to the respective unsilenced lines. This altered Na⁺/K⁺ ratio in flower tissues is associated with a sharp reduction in fruit yield, measured as total fresh weight and number of fruits, in both silenced lines under salinity conditions. Our findings demonstrate that Na⁺ transporter HKT1;2 protects the flower against Na⁺ toxicity and mitigates the reduction in tomato fruit yield under salinity conditions.

编码HKT1样Na ⁺转运蛋白的基因通过从不同器官和组织的木质部中提取Na ⁺在拟南芥和其他植物的耐盐性机制中起关键作用。在这项研究中，我们调查了在实际生产条件下在商业温室中进行盐处理的植物中，两个HKT1; 2等位基因变体在番茄耐盐性中与营养生长和果实产量相关的作用。我们在HKT1 ; 2基因座使用了两个近等基因系（NILs），它们分别是番茄茄（NIL17）或cheesmaniae（NIL14）等位基因纯合子，以及它们各自的RNAi- Sl / ScHKTT; 2。线。获得的结果表明，ScHKT1; 2-和SlHKT1; 2-沉默品系均显示出对盐度的超敏性，其与叶片Na ⁺ / K ⁺比例的变化有关，从而证实HKT1; 2在Na ⁺稳态和耐盐性中起重要作用。在番茄中。两条沉默线也均显示Na ⁺过度积累，并且盐处理植物的花组织中K ⁺含量略有但显着降低，因此与相应的非沉默线相比，Na ⁺ / K ⁺比率更高。这改变了Na ⁺ / K ⁺在盐度条件下，在两个沉默品系中，以总鲜重和果实数来衡量，花组织中的比率与果实产量的急剧下降有关。我们的发现表明，Na ⁺转运蛋白HKT1; 2保护花免受Na ⁺毒性，并减轻盐分条件下番茄果实产量的降低。