OsDGL1介导的细胞壁鼠李糖代谢参与调控水稻对缺氮诱导的初生根伸长响应OA

[Objective]Under nitrogen-deficient conditions,plants can enhance nitrogen uptake by promoting primary root growth;yet the molecular mechanisms underlying this adaptive response remain poorly understood.This study aimed to elucidate the intrinsic regulatory mechanisms of root morphological adaptation in rice in response to nitrogen deficiency,with a specific focus on clarifying the relationship between primary root growth regulation and nitrogen uptake efficiency.[Methods]Wild-type rice and the Osdgl1 mutant were used as experimental materials.Plants were subjected to either normal nitrogen supply or nitrogen-deficient conditions.Primary root growth phenotypes were systematically observed and measured.Concurrently,changes in the content of root cell wall components—including rhamnose,xylose,and cellulose,were analyzed.[Results]Nitrogen-deficient treatment significantly promoted primary root elongation of rice and partially restored the short-root phenotype of the Osdgl1 mutant.Genetic evidence indicated that OsDGL1 plays a crucial role in nitrogen deficiency-induced root growth.Further analysis revealed that changes in root length were primarily correlated with the content of rhamnose and xylose in the cell wall,but not with cellulose content.These findings suggest that rhamnose biosynthesis may serve an important function in this adaptive process.[Conclusion]OsDGL1 likely mediates the growth response of rice primary roots under nitrogen-deficient conditions by regulating the rhamnose biosynthesis pathway.This study provides novel insights and identifies future research directions for unraveling the molecular mechanisms through which nitrogen deficiency modulates root development in rice.