State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Taian, 271018, Shandong, People's Republic of China.
Plant Mol Biol. 2019 Mar;99(4-5):437-447. doi: 10.1007/s11103-019-00828-8. Epub 2019 Feb 2.
The expression of MdBBX10 was significantly induced by different stresses and ABA treatments. Overexpression of MdBBX10 in Arabidopsis significantly enhanced abiotic stresses tolerance by ABA signalling. The roles of B-box domain(s) containing proteins (BBXs) in regulation of flowering and light morphogenesis of plants were intensively studied. However, the roles of plant BBXs in abiotic stresses are poorly understood. A B-box protein encoding gene from apple (MdBBX10) was found to be up-regulated from gene expression profile under salt stress. qRT-PCR analysis indicated that the expression of MdBBX10 was significantly induced by different stresses and exogenous abscisic acid (ABA) in apple roots and leaves. The β-glucuronidase activity driven by the promoter of MdBBX10 was also strongly induced by NaCl, HO, polyethylene glycol and exogenous ABA, which was consistent to the existence of rich cis-acting elements related to the abiotic stresses in the promoter sequence. Over-expression of MdBBX10 in Arabidopsis significantly enhanced tolerance to abiotic stresses, with higher germination ratio and longer length of roots than the wild type plants. Transgenic plants of over-expressing MdBBX10 lines were more sensitive to exogenous ABA than the wild type plants. Under abiotic stress treatments, the transcript levels of ABA- and stress-related genes were higher in MdBBX10-overexpressing plants than wild type plants. Over-expression of MdBBX10 could enhance plant's ability to scavenge reactive oxygen species (ROS) under stresses, which is correlated with the expression of ROS-scavenging genes. These results provided the evidences that MdBBX10 plays an important role in enhanced plant tolerance to abiotic stresses, which were involved in ABA-mediated response and ROS response.
MdBBX10 的表达受不同胁迫和 ABA 处理的显著诱导。在拟南芥中过表达 MdBBX10 通过 ABA 信号显著增强了非生物胁迫耐受性。B-box 结构域（含）蛋白（BBXs）在植物开花和光形态建成中的调控作用得到了深入研究。然而，植物 BBXs 在非生物胁迫中的作用知之甚少。从盐胁迫下的基因表达谱中发现一种来自苹果的 B-box 蛋白编码基因（MdBBX10）上调。qRT-PCR 分析表明，MdBBX10 在苹果根和叶中的表达受不同胁迫和外源脱落酸（ABA）的显著诱导。MdBBX10 启动子驱动的β-葡萄糖醛酸酶活性也被 NaCl、HO、聚乙二醇和外源 ABA 强烈诱导，这与启动子序列中与非生物胁迫相关的丰富顺式作用元件的存在一致。在拟南芥中过表达 MdBBX10 显著增强了对非生物胁迫的耐受性，与野生型植物相比，萌发率更高，根更长。过表达 MdBBX10 的转基因植物对外源 ABA 比野生型植物更敏感。在非生物胁迫处理下，过表达 MdBBX10 植物中 ABA 和应激相关基因的转录水平高于野生型植物。过表达 MdBBX10 可以增强植物在胁迫下清除活性氧（ROS）的能力，这与 ROS 清除基因的表达有关。这些结果为 MdBBX10 在增强植物对非生物胁迫的耐受性中发挥重要作用提供了证据，这与 ABA 介导的反应和 ROS 反应有关。
