植物 SPX4 及 及 NUC 基因在营养吸收及根发育中新调控机制研究

	植物 SPX4 及及 NUC 基因在营养吸收及根发育中新调控机制研究; Novel Regulative Mechanisms of SPX4 and NUC Genes in Plant Nutrition Absorption and Root Development
	黄星
导师	李唯奇
摘要	This dissertation contains two parts. The first part reports a novel regulative mechanism of SYG/Pho81/XPR1 domain 4 (SPX4) gene. The second part reports a novel regulative mechanism of NUTCRACKER (NUC) gene. Phosphate (P) and nitrogen (N) are the two mineral nutrients which are the most needed in plants, and important nutrients to improve crop yield in agricultural production. Previous studies in Arabidopsis thaliana and rice have found that SPX4 plays an important role in P and N deficiency stress. SPX4 protein regulates the nucleocytoplasmic shuttle of P and N signaling pathway by ubiquitination to activate the P and N signal response. In the first part of the present study, we take Crucihimalaya Himalaica a close relative of A. thaliana but with superior tolerance for soil infertility as research material. We found that SPX4 gene of C. Himalaica has a novel regulation mechanism evolved during the long-term infertility adaptation of P and N signaling, and its alternative splicing form is reserved for introns. The main conclusions are as follows: (1) ChSPX4.1 is the conserved structure of SPX4 gene, while ChSPX4.2 is the unique spliceosome of C. Himalaica. The overexpression plants S1 and S2 were obtained respectively by overexpression two splicing isoforms ChSPX4.1 and ChSPX4.2 of C. himalaica SPX4 in A. thaliana Columbia. Then, C. himalaica (Ch), A. thaliana Columbia wild type (WT), S1 and S2 were used to study their response mechanism under P -, N - and NP - deficient stress, through physiological, molecular biology and lipidomics techniques. (2) Both S1 and S2 plants showed earlier flowering than WT, while increased seed weight was observed in S2 plants, which may be more conducive to their response to environmental stress. (3) S1 and S2 showed excellent characteristics under P deficient stress. They had less anthocyanin accumulation in leaves, faster growth and development, significantly higher root/shoot ratio, and could more stable root tip cell structure than WT. Under short-term and long-term P-deficient conditions, the P-responsive genes of S1 and S2 maintained high expression levels, which could quickly initiate P starvation response, and thus better tolerance under P deficient stress. Subcellular localization showed that ChSPX4.1 was mainly located in cytoplasm and a few in nucleus, while ChSPX4.2 was distributed in both cytoplasm and nucleus. Protein interaction showed that ChSPX4.1 and ChSPX4.2 were distributed in both cytoplasm and nucleus after binding with PHR1. ChSPX4.1-PHR1 dimer was only distributed in cytoplasm, while ChSPX4.2-PHR1 dimer was highly expressed in both cytoplasm and nucleus. Therefore, ChSPX4.1 may function in the common mechanism of rice and A. thaliana SPX4, while ChSPX4.2 have a new mechanism of function. (4) S1 and S2 also showed better characteristcs under N and NP stress, with less anthocyanin accumulation in leaves, higher root shoot ratio and faster growth and development. Under N deficient stress, the
	2021-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74631
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	黄星. 植物 SPX4 及及 NUC 基因在营养吸收及根发育中新调控机制研究, Novel Regulative Mechanisms of SPX4 and NUC Genes in Plant Nutrition Absorption and Root Development[D],2021.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
黄星-黄星-毕业论文186e21ba-1（33059KB）	学位论文		限制开放	CC BY-NC-SA	请求全文