拟南芥NUC基因在植物缺氮和缺磷胁迫中的功能研究

	拟南芥NUC基因在植物缺氮和缺磷胁迫中的功能研究; Functional characterization of NUC gene under nitrogen and phosphorus deficiency stress in Arabidopsis thaliana
	凌静
导师	李唯奇
摘要	Nutrients play a crucial role in plant growth and development, which not only participate in the construction of plant structure, but also regulate the physiological functions. Plants obtain nutrients from the environments through root systems. However, the environmental nutrients often fluctuate and limited, resulting in nutrient stresses to plants. Nitrogen (N) and phosphorus (P) are crucial nutrients for plants. N and P deficiency are also common limited factors for crop development and productivity. NUTCRACKER (NUC) is a transcription factor expressed in multiple tissues. To the best of our knowledge, only two cases of its physiological roles, regulating asymmetric cell division of root tip cell and flowering, have been reported thus far. Whether NUC has other roles remains unknown. In this study, we explore the other physiological functions of NUC with Arabidopsis thaliana Col, NUC T-DNA insertion deletion mutants (nuc1-1 and nuc1-3), NUC-overexpression lines (OE-1, OE-4 and OE-5) and nuc1-3 rescue line (ProNUC::NUC). We found that NUC functions in plant growth and development and responses to nutrient stress. Our main conclusions are as follows: 1. NUC has an extensive effect on promoting plant growth and development. Overexpression of NUC promotes development at the seed germination, hypocotyl and seedling development. However, loss of NUC does not affect these development processes, possibly because its roles in these processes are redundant with its homologous proteins JACKDAW (JKD) and MAGPIE (MGP). 2. Overexpression of NUC enhances the resistance to N deficiency stress. In sterile seedlings culture, we find that NUC overexpression lines significantly grow better than Col under N deficiency. In hydroponic culture, we find that NUC overexpression lines show lower anthocyanin content and higher biomass than Col under N deficiency. 3. Overexpression of NUC attenuates the P-deficiency-induced development inhibition. In sterile seedlings culture, we find that overexpression of NUC significantly attenuates the development inhibition of leaves under P deficiency. In hydroponic culture, we find that overexpression of NUC significantly attenuates the reduction of chlorophyll, the accumulation of anthocyanin and the loss of biomass in Arabidopsis under P deficiency. 4. Expression of NUC is lower in leaves but higher in roots under normal growth conditions. NUC is remarkably induced by N deficiency and P deficiency in leaves, respectively. In contrast, its expression is remarkably induced only by P deficiency and not affected by N deficiency in roots. 5. Overexpression of NUC promotes primary root elongation and the promotion is constitutive, neither affecting by N deficiency nor P deficiency. Microscopic observation shows that overexpression of NUC increases meristem cell number and elongation zones. The constitutively longer primary roots in NUC overexpression lines could be one of the factors for their higher resistance to N deficiency and P
	2021-11
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74572
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	凌静. 拟南芥NUC基因在植物缺氮和缺磷胁迫中的功能研究, Functional characterization of NUC gene under nitrogen and phosphorus deficiency stress in Arabidopsis thaliana[D],2021.

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