Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Planta. 2019 Jun;249(6):1851-1861. doi: 10.1007/s00425-019-03125-2. Epub 2019 Mar 8.
Morphological, physiological, and gene expression analyses showed that Os4BGlu10, Os6BGlu24, and Os9BGlu33 played specific roles in seed germination, root elongation, and drought tolerance of rice, with various relations with indole-3-acetic acid (IAA) and abscisic acid (ABA) signaling. β-Glucosidases (BGlus) belong to glycoside hydrolase family 1 and have many functions in plants. In this study, we investigated the function of three BGlus in seed germination, drought tolerance, and root elongation using the loss-of-function mutants bglu10, bglu24, and bglu33. These mutants germinated slightly later under normal conditions and had significantly longer roots than the wild type. In the presence of ABA, bglu10 and bglu24 exhibited a higher germination inhibition percentage, whereas bglu33 had a lower germination inhibition percentage, compared to the wild type. All of the mutants exhibited less drought tolerance, with the survival rates significantly lower than that of the wild type, which was also confirmed by a decrease in relative leaf water content and Fv/Fm ratio after drought treatment. The root length of bglu10 did not respond to IAA, whereas that of bglu24 responded to a high (0.25 µM) concentration of IAA, and that of bglu33 to a low (0.05 µM) concentration of IAA. The root length of bglu10 and bglu24 did not respond to ABA, whereas that of bglu33 increased significantly in response to a high (0.05 µM) concentration of ABA. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that expression of Os4BGlu10 was up-regulated by polyethylene glycol (PEG), whereas that of Os6BGlu24 was up-regulated by 0.25 µM IAA, and Os9BGlu33 was up-regulated by PEG, IAA, and ABA. Taken together, we demonstrate that Os4BGlu10, Os6BGlu24, and Os9BGlu33 play specific roles in seed germination, root elongation, and drought tolerance with various relation with IAA and ABA signaling.
形态学、生理学和基因表达分析表明，Os4BGlu10、Os6BGlu24 和 Os9BGlu33 在水稻种子萌发、根伸长和耐旱性方面发挥了特定作用，与吲哚-3-乙酸（IAA）和脱落酸（ABA）信号有各种关系。β-葡萄糖苷酶（BGlus）属于糖苷水解酶家族 1，在植物中有许多功能。在这项研究中，我们使用功能丧失突变体 bglu10、bglu24 和 bglu33 研究了三种 BGlus 在种子萌发、耐旱性和根伸长中的功能。这些突变体在正常条件下发芽稍晚，根明显比野生型长。在 ABA 存在下，bglu10 和 bglu24 的发芽抑制率更高，而 bglu33 的发芽抑制率更低，与野生型相比。所有突变体的耐旱性都较低，存活率明显低于野生型，这也通过干旱处理后相对叶片含水量和 Fv/Fm 比值的降低得到证实。bglu10 的根长对 IAA 没有反应，而 bglu24 的根长对 0.25 μM 的高浓度 IAA 有反应，bglu33 的根长对 0.05 μM 的低浓度 IAA 有反应。bglu10 和 bglu24 的根长对 ABA 没有反应，而 bglu33 的根长在 0.05 μM 的高浓度 ABA 存在下显著增加。定量实时聚合酶链反应（qRT-PCR）分析表明，Os4BGlu10 的表达受聚乙二醇（PEG）上调，而 Os6BGlu24 的表达受 0.25 μM IAA 上调，Os9BGlu33 的表达受 PEG、IAA 和 ABA 上调。综上所述，我们证明 Os4BGlu10、Os6BGlu24 和 Os9BGlu33 在种子萌发、根伸长和耐旱性方面发挥了特定作用，与 IAA 和 ABA 信号有各种关系。
