异源过表达OsATG8b基因提高转基因拟南芥的氮/碳胁迫耐受性和产量

Heterologous Overexpression of Autophagy-related Gene OsATG8b from Rice Confers Tolerance to Nitrogen/Carbon Starvation and Increases Yield in Arabidopsis

氮素是参与植物生长发育的一种重要元素,对植物的产量和品质具有重要作用。自噬是真核生物中一种保守的细胞组分降解-循环再利用途径,在植物生长发育和籽粒形成期间的氮素再动员过程中发挥作用。我们鉴定到水稻(Oryza sativa)自噬核心基因OsATG8b,并获得2个独立的35S-OsATG8b转基因拟南芥(Arabidopsisthaliana)纯合株系。研究表明OsATG8b基因响应低氮胁迫处理,过表达OsATG8b基因促进转基因拟南芥的生长发育,使莲座叶增大,单株产量显著提高(15.16%)。进一步研究表明,过表达OsATG8b能够显著增强缺氮胁迫下转基因拟南芥叶片中的自噬活性,从而有效缓解氮胁迫和碳胁迫对转基因拟南芥造成的生长抑制。因此, OsATG8b是提高氮素利用效率和产量的候选基因。

Nitrogen is an essential element for plant growth and development and plays an important role in plant yield and quality. Autophagy is a conserved degradation-recycle pathway of cellular components in eukaryotes that plays an important role in nitrogen remobilization during plant growth and grain formation. We identified an autophagy core gene OsATG8b in rice and obtained 2 independent 35S-OsATG8b transgenic Arabidopsis homozygous lines. The expression of Os ATG8b responded to nitrogen starvation in rice. Overexpression of OsATG8b promoted the growth and development of transgenic Arabidopsis, with rosette leaves larger than wild-type leaves. In addition, the yield increased significantly, by 15.16%. In addition, overexpression of OsATG8b could significantly enhance autophagic activity in leaves of transgenic Arabidopsis under nitrogen deficiency and effectively alleviate the growth inhibition of transgenic Arabidopsis caused by nitrogen and carbon stress. OsATG8b may be a good candidate gene for increasing nitrogen use efficiency and yield.