Preferential assimilation of NH4+ over NO3- in tea plant associated with genes involved in nitrogen transportation, utilization and catechins biosynthesis
Preferential assimilation of NH4+ over NO3- in tea plant associated with genes involved in nitrogen transportation, utilization and catechins biosynthesis
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茶树中 NH4 优先同化 NO3- 与涉及氮运输、利用和儿茶素生物合成的基因相关
DOI：
10.1016/j.plantsci.2019.110369
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发表时间：
2020
期刊：
影响因子：
5.2
通讯作者：
Ruan Jianyun
中科院分区：
文献类型：
--
作者：
Tang D;an;Liu Mei-Ya;Zhang Qunfeng;Ma Lifeng;Shi Yuanzhi;Ruan Jianyun
铵态氮（NH 4+）和硝酸盐（NO3−）对茶树的生理效应已经证实，茶树更喜欢NH 4+作为氮（N）的主要来源。为了研究这种偏好的可能解释，使用水培生长的茶树进行了15 NH 4+和15 NO3 −同化的研究。在15 NH 4+和15 NO3 −同化过程中，由于NH 4+转运蛋白的表达模式比NO3−转运蛋白的表达模式更有效，因此茶树对15 NH 4+的吸收比对15 NO3 −的吸收更快。15 NH 4+处理的茶树比15 NO3 −处理的茶树积累更多的15 N，这一点可以从与初级N同化相关的基因CsNR、CsNiR、CsGD和CsGOGAT，受15 NH 4+的影响大于受15 NO3-的影响。与NO3−处理相比，15个NH 4+处理的茶树根系中NH 4+浓度显著较高，而茶树在这两种氮形态下都保持了茶叶中NH 4+的平衡浓度。这种维持是通过增加参与茶氨酸生物合成的基因的表达和抑制与来自苯丙烷途径的儿茶素相关的基因来实现的。目前的研究结果表明，有效的NH 4+运输，同化和再利用，使茶树作为一个铵偏好植物物种。
Physiological effects of ammonium (NH4+) and nitrate (NO3−) on tea have confirmed that tea plants prefer NH4+as the dominant nitrogen (N) source. To investigate the possible explanations for this preference, studies of15NH4+and15NO3− assimilation using hydroponically grown tea plants were conducted. During the time course of15NH4+and15NO3−assimilation, the absorption of15N from15NH4+was more rapid than that from15NO3−, as there was a more efficient expression pattern of NH4+transporters compared with that of NO3−transporters.15NH4+-fed tea plants accumulated more15N than15NO3−fed plants, which was demonstrated by that genes related to primary N assimilation, likeCsNR,CsNiR,CsGDHandCsGOGAT, were more affected by15NH4+than15NO3−. Markedly higher NH4+concentrations were observed in15NH4+-fed tea roots in comparison with NO3−treatment, whereas tea plants maintained a balanced concentration of NH4+in tea leaves under both these two N forms. This maintenance was achieved through the increased expression of genes involved in theanine biosynthesis and the inhibition of genes related to catechins derived from phenylpropanoid pathway. The current results suggest that efficient NH4+transportation, assimilation, and reutilization enables tea plant as an ammonium preferring plant species.