Ullah Mohammad Asad, Abdullah-Zawawi Muhammad-Redha, Razalli Izreen Izzati, Sukiran Noor Liyana, Uddin Md Imtiaz, Zainal Zamri
Faculty of Science & Technology, Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, 43600, Malaysia.
Bangladesh Institute of Nuclear Agriculture (BINA), BAU Campus, Mymensingh, 2202, Bangladesh.
Mol Biol Rep. 2024 Dec 7;52(1):40. doi: 10.1007/s11033-024-10130-6.
Rice is subjected to various environmental stresses, resulting in significant production losses. Abiotic stresses, particularly drought and salinity, are the leading causes of plant damage worldwide. The High-affinity Potassium Transporter (HKT) gene family plays an important role in enhancing crop stress tolerance by regulating physiological and enzymatic functions.
This study investigates the effect of overexpressing the rice HKT1;5 gene in Arabidopsis thaliana on its tolerance to salinity and drought. The OsHKT1;5 gene was introduced into Arabidopsis under the control of 35 S promoter of CaMV via floral dip transformation method. PCR confirmed the integration of the transgene into the Arabidopsis genome, while qPCR analysis showed its expression. Three transgenic lines of OsHKT1;5 were used for stress treatment and phenotypic studies. The overexpressed lines showed considerably higher germination rates, increased leaf counts, greater fresh and dry weights of the roots and shoots, higher chlorophyll contents, longer root lengths, and reduced Na levels together with increased K ions levels after salt and drought treatments, in comparison to wild-type plants. Furthermore, overexpressed lines exhibited higher antioxidant levels than wild-type plants under salinity and drought conditions. In addition, transgenic lines showed higher expression levels of the OsHKT1;5 gene in both roots and shoots compared to wild-type plants.
In conclusion, this study revealed OsHKT1;5 as a promising candidate for enhancing tolerance to salinity and drought stresses in rice, marking a significant step toward developing a new rice variety with improved abiotic stress tolerance.
水稻遭受各种环境胁迫，导致产量大幅损失。非生物胁迫，尤其是干旱和盐碱化，是全球范围内植物受损的主要原因。高亲和性钾转运体（HKT）基因家族通过调节生理和酶功能，在增强作物胁迫耐受性方面发挥重要作用。
本研究调查了在拟南芥中过表达水稻HKT1;5基因对其耐盐性和耐旱性的影响。通过花浸转化法，将OsHKT1;5基因在CaMV的35S启动子控制下导入拟南芥。PCR证实转基因已整合到拟南芥基因组中，而qPCR分析显示了其表达。使用三个OsHKT1;5转基因株系进行胁迫处理和表型研究。与野生型植株相比，过表达株系在盐胁迫和干旱处理后表现出显著更高的发芽率、叶片数量增加、根和地上部分的鲜重和干重更大、叶绿素含量更高、根更长、Na水平降低以及K离子水平升高。此外，在盐胁迫和干旱条件下，过表达株系的抗氧化水平高于野生型植株。另外，与野生型植株相比，转基因株系在根和地上部分中OsHKT1;5基因的表达水平更高。
总之，本研究表明OsHKT1;5是增强水稻耐盐性和耐旱性的一个有潜力的候选基因，标志着在培育具有 improved abiotic stress tolerance的新水稻品种方面迈出了重要一步。（注：原文中“improved abiotic stress tolerance”可能表述有误，推测应为“提高非生物胁迫耐受性”之类意思，此处按原文准确翻译）
