长期干旱胁迫下Mdm-miR160-MdARF17-MdHYL1模块调控苹果生长发育的研究

Regulation of Apple Growth and Development by Mdm-miR160-MdARF17 - MdHYL1 Module under Long-term Drought Stress

为了研究长期干旱条件下Mdm-miR160- MdARF17- MdHYL1调控网络在苹果生长发育中的作用,以GL-3和Mdm-miR160e OE、 MdARF17RNAi、 MdmARF17OE、 MdHYL1OE及 MdHYL 1 RNAi转基因苹果为试验材料,进行为期3个月的长期干旱处理,测定苹果株高、根干质量、根冠比以及叶片净光合速率、胞间CO_(2)浓度、气孔导度、蒸腾速率、叶绿素荧光值和水分利用效率。结果表明,在长期干旱胁迫下,Mdm-miR160e OE转基因苹果植株更矮化,根冠比、根干质量、光合能力及水分利用效率大于GL-3植株,具有更强的耐旱性;MdARF17 RNAi植株比GL-3更矮,且具有更大的根冠比、根干质量、光合能力和水分利用效率,而 MdARF17OE与之相反;MdHYL1RNAi植株对长期干旱胁迫更敏感,其株高大于野生型且具有更小的根冠比、更低的光合能力和水分利用效率,而 MdHYL1OE植物对长期干旱条件具有更强的适应性,生长发育表型与RNAi植株相反。综上所述,Mdm-miR160- MdARF17- MdHYL1调控网络在苹果响应长期干旱过程中发挥了重要功能,为苹果抗旱分子育种提供了候选基因。

GL-3 and Mdm-miR160e OE,MdARF17 RNAi,MdmARF17 OE,MdHYL1 OE,MdHYL1 RNAi transgenic apples were used as materials to investigate the role of Mdm-miR160-MdARF17-MdHYL1 regulatory network in growth and development of apple trees under long-term drought stress,after three months of drought treatment,we measured plant height,root dry mass,root to shoot ratio,and leaf net photosynthetic rate,intercellular CO_(2) concentration,stomatal conductance,transpiration rate,F v/F m and water use efficiency.The results showed that under long-term drought stress,compared with GL-3 plants,Mdm-miR160e OE transgenic apple plants exhibited a more dwarf symptom,with a higher root-to-shoot ratio,root mass,photosynthetic capacity,and water use efficiency compared to GL-3 plants.They demonstrated a stronger drought tolerance;MdARF17 RNAi plants were shorter than GL-3,with a higher root to shoot ratio,greater root dry mass,enhanced photosynthetic capacity,and improved water use efficiency.In contrast,MdARF17 OE plants displayed characteristics opposite to those of MdARF17 RNAi lines.MdHYL1 RNAi plants were more sensitive to long-term drought stress,with higher plant height compared to the wild-type,a smaller root-to-shoot ratio,lower photosynthetic capacity,and reduced water use efficiency.On the other hand,MdHYL1 OE plants were better adapted to long-term drought conditions and exhibited phenotypes that were the opposite of those seen in MdHYL1 RNAi lines.Therefore,Mdm-miR160-MdARF17-MdHYL1 regulatory network plays an important role in apple responses to long-term drought stress and provides candidate genes for molecular breeding to enhance drought resistance.