花魔芋球茎发育期氮分配变化和相关基因表达分析  

Nitrogen Allocation Characteristics and Expression of Related Genes During Corm-Forming Stage of Amorphophallus konjac

作　　者：任思源 陈森 龙治坚[1] 王博雅 唐登国 王正前 杨斌 胡尚连[1] 曹颖[1] REN Siyuan;CHEN Sen;LONG Zhijian;WANG Boya;TANG Dengguo;WANG Zhengqian;YANG Bin;HU Shanglian;CAO Ying(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;Guangyuan Yinong Biotechnology Co.,Ltd.,Guangyuan,Sichuan 628017,China;Xuanhan Agricultural Science and Technology Research Institute,Xuanhan,Sichuan 636150,China)

机构地区：[1]西南科技大学生命科学与工程学院,四川绵阳621010 [2]广元益农生物科技有限责任公司,四川广元628017 [3]宣汉农业科技研究所,四川宣汉636150

出　　处：《园艺学报》2024年第9期2019-2030,共12页Acta Horticulturae Sinica

基　　金：国家现代农业产业技术体系四川创新团队项目(SC-CXTD-2023-12)。

摘　　要：利用^(15)N同位素示踪和转录组测序,系统地研究了花魔芋(Amorphophallus konjac K. Koch)球茎发育过程中各器官氮素分配特征,以及氮代谢相关基因表达情况,以理解氮素利用情况并指导合理用肥。结果表明,在球茎发育过程中,叶片的含氮量最高;随球茎膨大,叶片的含氮量、Ndff值、^(15)N分配率和利用率呈下降趋势,而球茎对氮素的需求增加,^(15)N利用率高峰出现在球茎膨大中后期(散叶后45~75 d)。整个植株^(15)N利用率呈现先增加后降低的趋势,在散叶后60 d时整个植株中的N含量达到峰值,^(15)N利用率最高,为22.68%,之后在各个器官中N素含量与^(15)N利用率均逐步降低,说明在60d时是氮素的最大利用效率期,从此开始植物吸收的氮素由主要分配给叶片转向分配给球茎,此时为追施氮肥的适宜期。叶片中氮代谢相关基因表达高峰出现在球茎膨大中后期(散叶后105d),此时叶片的氮代谢反应加强,有利于氮同化产物合成和输出。叶片中硝酸还原酶基因AkNIA1和谷氨酰胺合成酶基因AkGSR2-1表达水平与叶片和根中N含量显著正相关,表明其在促进氮吸收和氮积累中的重要作用,可作为氮利用率遗传改良的候选基因。Through ^(15)N 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,^(15)N distribution rate and ^(15)N utilization rate in leaves showed a downward trend,whereas the N demand in corms increased,the peak of ^(15)N 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 ^(15)N content of in a whole plant at 60 d,while the ^(15)N utilization rate also reached the highest rate of 22.68%.Then,both the content and utilization rate of ^(15)N 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.

关 键 词：花魔芋 氮素分配 氮代谢 基因表达 球茎 ^(15)N同位素示踪 

分 类 号：S632[农业科学—蔬菜学]