Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China.
Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.
BMC Plant Biol. 2021 Feb 17;21(1):97. doi: 10.1186/s12870-021-02868-z.
Banana is a tropical fruit with a high economic impact worldwide. Cold stress greatly affects the development and production of banana.
In the present study, we investigated the functions of MaMAPK3 and MaICE1 involved in cold tolerance of banana. The effect of RNAi of MaMAPK3 on Dajiao (Musa spp. 'Dajiao'; ABB Group) cold tolerance was evaluated. The leaves of the MaMAPK3 RNAi transgenic plants showed wilting and severe necrotic symptoms, while the wide-type (WT) plants remained normal after cold exposure. RNAi of MaMAPK3 significantly changed the expressions of the cold-responsive genes, and the oxidoreductase activity was significantly changed in WT plants, while no changes in transgenic plants were observed. MaICE1 interacted with MaMAPK3, and the expression level of MaICE1 was significantly decreased in MaMAPK3 RNAi transgenic plants. Over-expression of MaICE1 in Cavendish banana (Musa spp. AAA group) indicated that the cold resistance of transgenic plants was superior to that of the WT plants. The POD P7 gene was significantly up-regulated in MaICE1-overexpressing transgenic plants compared with WT plants, and the POD P7 was proved to interact with MaICE1.
Taken together, our work provided new and solid evidence that MaMAPK3-MaICE1-MaPOD P7 pathway positively improved the cold tolerance in monocotyledon banana, shedding light on molecular breeding for the cold-tolerant banana or other agricultural species.
香蕉是一种具有全球高经济影响力的热带水果。冷胁迫极大地影响了香蕉的发育和生产。
在本研究中，我们研究了参与香蕉耐寒性的 MaMAPK3 和 MaICE1 的功能。评估了 RNAi 沉默 MaMAPK3 对大蕉（Musa spp. 'Dajiao'；ABB 群）耐寒性的影响。MaMAPK3 RNAi 转基因植物的叶片出现萎蔫和严重坏死症状，而宽型（WT）植物在冷暴露后仍保持正常。MaMAPK3 的 RNAi 显著改变了冷响应基因的表达，而 WT 植物的氧化还原酶活性发生了显著变化，而转基因植物则没有观察到变化。MaICE1 与 MaMAPK3 相互作用，MaMAPK3 RNAi 转基因植物中 MaICE1 的表达水平显著降低。在卡文迪什香蕉（Musa spp. AAA 群）中过表达 MaICE1 表明，转基因植物的抗寒性优于 WT 植物。与 WT 植物相比，过表达 MaICE1 的转基因植物中 POD P7 基因显著上调，并且证明 POD P7 与 MaICE1 相互作用。
综上所述，我们的工作提供了新的、可靠的证据，表明 MaMAPK3-MaICE1-MaPOD P7 途径正向提高了单子叶香蕉的耐寒性，为耐寒香蕉或其他农业物种的分子育种提供了线索。
