Nitrogen Allocation Characteristics and Expression of Related Genes During Corm-Forming Stage of Amorphophallus konjac
Through 15N isotopic tracing and RNA-seq analysis,the N distribution in various organs and the expression of genes related to N during the development of konjac corms are systematically studied would help to understand nitrogen utilization and guide the fertilizer use.Results show that during the development of Amorphophallus konjac corms the N content per unit weight of leaves was the highest as the compared with other organs.During the expansion of corms,N content,Ndff value,15N distribution rate and 15N utilization rate in leaves showed a downward trend,whereas the N demand in corms increased,the peak of 15N utilization rate appearing right in the middle stage of corm expansion(45-75 d,day after expansion of leaves).A.konjac reached the peak of 15N content of in a whole plant at 60 d,while the 15N utilization rate also reached the highest rate of 22.68％.Then,both the content and utilization rate of 15N were deceasing,indicating that this point was the most efficiently nitrogen use period.After 60 d,the absorbed nitrogen was distributed from leaves to corms,which also invalided that 60 d was the suitable period for N topdressing.Meanwhile,the peak of expression in N metabolism-related genes in leaves appeared between the middle and late stage of corm expansion(105 d),a range within which leaf N metabolism was strengthened,promoting the synthesis and output of N assimilation products.Among them,the expression levels in leaves of nitrate reductase gene AkNIA1 and glutamine synthetase gene AkGSR2-1 were significantly and positively correlated with the N content in leaves and roots,indicating their key role in nitrogen absorption and accumulation,and they can be used as candidate genes for genetic improvement of N utilization.
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万方数据
