加速花分生组织(FM)与茎尖分生组织(SAM)的分化,这决定了从营养生长到生殖生长的转化,对于油菜(BrassicanapusL.)的生产具有重要意义。在这项研究中,不同氮(N)施用量(低氮,N1;正常N,N2;和高N,N3)对FM不同发育阶段通过生长素生物合成和信号转导引发FM分化基因的调控进行了研究。我们发现FM分化的阶段,通过立体显微镜和扫描电子显微镜鉴定,在高N率下比正常和低N水平下早4天和7天,种子产量分别增加了11.1%和22.6%,分别。对生长素及其衍生物含量的分析表明,生长素的生物合成途径主要为吲哚乙醛肟(IAOx)途径,3-吲哚乙腈在FM分化过程中急剧积累。同时,在每个FM分化阶段检测到IAA含量明显下降,然后逐渐上升。生长素生物合成相关基因的表达结果,生长素信号转导,在5个FM分化阶段和3个施氮量下的FM鉴定表明,参与生长素生物合成的基因在FM分化阶段之前受到调控,而FM身份基因的调控主要出现在五个阶段的中后期,基因的调控水平在不同的氮速率下有所不同。一起来看,高氮率可以加速FM分化的开始,和生长素在这个法规中涉及很多。
Accelerating the differentiation of floral meristem (FM) from shoot apical meristems (SAM) which determines the conversion from vegetative to reproductive growth is of great significance for the production of rapeseed (Brassica napus L.). In this research, the mechanisms of different nitrogen (N) application rates (low N, N1; normal N, N2; and high N, N3) on different FM development stages triggering the regulation of FM differentiation genes through the auxin biosynthetic and signal transduction were investigated. We found that the stage of FM differentiation, which was identified through a stereomicroscope and scanning electron microscope, came 4 and 7 days earlier under high N rate than under normal and low N levels, with the seed yield increased by 11.1 and 22.6%, respectively. Analysis of the auxin and its derivatives contents showed that the main biosynthesis way of auxin was the indole acetaldehyde oxime (IAOx) pathway, with 3-Indole acetonitrile dramatically accumulated during FM differentiation. At the same time, an obvious decrease of IAA contents at each FM differentiation stage was detected, and then gradually rose. Results of the expression of genes involved in auxin biosynthesis, auxin signaling transduction, and FM identification under five FM differentiation stages and three nitrogen application rates showed that genes involved in auxin biosynthesis were regulated before the FM differentiation stage, while the regulation of FM identity genes appeared mainly at the middle and later periods of the five stages, and the regulation level of genes varied under different N rates. Taken together, a high nitrogen rate could accelerate the initiation of FM differentiation, and auxin involved a lot in this regulation.