硝态氮调控拟南芥开花时间的分子机制研究

	硝态氮调控拟南芥开花时间的分子机制研究; Molecular genetic mechanisms of flowering time variation in responding to nitrate fluctuation in Arabidopsis thaliana
	燕飞虹
导师	胡金勇
摘要	Flowering time, a key transition point from vegetative to reproductive growth, is regulated by intrinsic complex of endogenous and exogenous signals. Nitrogen as the essential macronutrient, its deficiency often induces early flowering. But the molecular genetic basis on how plants adapting to ever-changing nitrogen availability remains not fully explored. The mechanism of how flowering time is regulated has gained much knowledge in Arabidopsis thaliana. However, the exact role of nitrate in regulating the flowering time of naturally occurring accessions and the underlying molecular mechanism remains obscure. And the regulation of nitrate metabolism genes in flowering time is largely unknown in Arabidopsis. Here we conducted our experiments in two aspects. Molecular genetic mechanisms of flowering time variation in responding to nitrate fluctuation in Arabidopsis accessions. In this experiment, three widely used natural variations of Arabidopsis (Col-0, Ws and Ler) were planted in agar medium that contain different concentrations (0.5, 1, 2, 4, 8, 16, 32 mM) of KNO3 to study its flowering time variation as nitrate fluctuation in LD and MD conditions. Upon nitrate availability changes, we detected a genotype- and photoperiod- specific flowering responses. Under LD condition, the flowering time of Ler and Col-0 has the similar response to nitrate, and Ws was the weakest. Under MD condition, all three accessions flowered significantly later than those growing under LD condition, the flowering time of both Ws and Ler displayed very little variation in their flowering time when grown on different concentrations of KNO3, but Col-0 was more sensitive than under LD condition obviously. Through RT-qPCR, we found that flowering time variation correlates well with the expression of floral integrators, SOC1 and FT, in an accession-specific manner, the expression of key hub genes in photoperiod (GI) , aging (SPLs) and autonomous (FLC) pathways associates with the expression change of these integrators, hence flowering time variation. In summary, we reveal a genotype- and photoperiod- specific flowering responses upon changing of nitrate availability, and this associates well with the genotype-specific expression of key flowering time genes, such as FT and SOC1; We identified 7 loss-of-function mutants about nitrate metabolism flower earlier than wild type significantly; Found the interaction between ANR1 and the flowering factor AGL16. This paper not only enriched the regulatory network of flowering time in Arabidopsis, It also laid an important foundation for revealing the coordination mechanism between nitrate and the flowering time.
	2020-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74200
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	燕飞虹. 硝态氮调控拟南芥开花时间的分子机制研究, Molecular genetic mechanisms of flowering time variation in responding to nitrate fluctuation in Arabidopsis thaliana[D],2020.

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