Colege of Horticulture, Gansu Agricultural University, Lanzhou, China.
Plant Biol (Stuttg). 2023 Oct;25(6):892-901. doi: 10.1111/plb.13559. Epub 2023 Aug 28.
As one of the major abiotic stresses restricting the development of global agriculture, saline-alkali stress causes osmotic stress, ion poisoning, ROS damage and high pH damage, which seriously restrict sustainable development of fruit industry. Therefore, it is essential to develop and cultivate saline-alkali-resistant apple rootstocks to improve the yield and quality of apples in China. Based on transcriptome data, MhANR (LOC114827797), which is significantly induced by saline-alkali stress, was cloned from Malus halliana. The physicochemical properties, evolutionary relationships and cis-acting elements were analysed. Subsequently, the tolerance of MhANR overexpression in Arabidopsis thaliana, tobacco, and apple calli to saline-alkali stress was verified through genetic transformation. Transgenic plants contained less Chl a, Chl b and proline, SOD, POD and CAT activity, and higher relative electrical conductivity (REC) compared to WT plants under saline-alkali stress. In addition, expression of saline-alkali stress-related genes in overexpressed apple calli were also lower than in WT calli, including the antioxidant genes (MhSOD and MhCAT^), the Na transporter genes (MhCAX5, MhCAX5, MhSOS1, MhALT1), and the H -ATPase genes (MhAHA2 and MhAHA8), while expression of the K transporter genes (MhSKOR and MhNHX4) were higher. Expression of MhANR reduced tolerance of A. thaliana, tobacco, and apple calli to saline-alkali stress by regulating osmoregulatory substances, chlorophyll content, antioxidant enzyme activity, and expression of saline-alkali stress-related genes. This research provides a theoretical basis for cultivating apple rootstocks with effective saline-alkali stress tolerance.
作为限制全球农业发展的主要非生物胁迫之一，盐碱性胁迫会导致渗透胁迫、离子中毒、ROS 损伤和高 pH 损伤，严重限制了水果产业的可持续发展。因此，培育耐盐碱性苹果砧木对于提高我国苹果的产量和品质至关重要。本研究基于转录组数据，从山定子（Malus halliana）中克隆出一个受盐碱性胁迫显著诱导的基因 MhANR（LOC114827797）。分析了其理化性质、进化关系和顺式作用元件。随后，通过遗传转化验证了 MhANR 在拟南芥、烟草和苹果愈伤组织中对盐碱性胁迫的耐受性。与野生型（WT）植物相比，转基因植物在盐碱性胁迫下叶绿素 a、叶绿素 b 和脯氨酸含量较低，SOD、POD 和 CAT 活性较高，相对电导率（REC）较高。此外，在过表达苹果愈伤组织中，与盐碱性胁迫相关的基因（抗氧化基因 MhSOD 和 MhCAT^、Na 转运基因 MhCAX5、MhCAX5、MhSOS1、MhALT1 和 H+-ATPase 基因 MhAHA2 和 MhAHA8）的表达也低于 WT 愈伤组织，而 K 转运基因（MhSKOR 和 MhNHX4）的表达则较高。MhANR 的表达通过调节渗透调节物质、叶绿素含量、抗氧化酶活性和盐碱性胁迫相关基因的表达，降低了拟南芥、烟草和苹果愈伤组织对盐碱性胁迫的耐受性。本研究为培育具有有效耐盐碱性的苹果砧木提供了理论依据。
