Differential responses of root growth to nutrition with different ammonium/nitrate ratios involve auxin distribution in two tobacco cultivars

文献类型： 外文期刊

第一作者： Meng Lin

作者： Meng Lin;Dong Jian-xin;Wang Shu-sheng;Song Ke;Yang Jin-guang;Song Wen-jing;Liang Hong-bo;Ling Ai-fen;Xiao Zhi-xin;Li Wei

作者机构：

关键词： auxin; lateral root; formation and elongation; tobacco; NH4+/NO3- ratio

期刊名称：JOURNAL OF INTEGRATIVE AGRICULTURE （ 影响因子：2.848； 五年影响因子：2.979 ）

ISSN： 2095-3119

年卷期： 2019 年 18 卷 12 期

页码：

收录情况： SCI

摘要： Nitrogen (N), the major forms of which are nitrate (NO3-) and ammonium (NH4+), plays an important role in plant growth and mediation of root development. However, the role of auxin in root growth in response to different NH4+/NO3- ratios remains unclear. Two tobacco cultivars (Nicotiana tabacum L.) were adopted in this study, which displayed variant growth features under the situations with sole NO3- nutrition ratio (NH4+/NO3- ratio: 0/100), low NO3- nutrition ratio (NH4+/NO3- ratio: 97/3), and optimal NH4+/NO3- ratio (50/50). We investigated the effects of the different NH4+/NO3- ratios on the formation and elongation of lateral roots (LRs), auxin concentration, DR5::GUS expression, H-3-labeled indole acetic acid ([H-3]IAA) transport, and the expression of six PIN genes in tobacco roots. We also examined the effects of exogenous auxin and a transport inhibitor on LRs growth. The results are shown as follows, compared to optimal N nutrition conditions, the biomass and nitrogen (N) accumulation were largely reduced by sole and low NO3- nutrition treatment in NC89, but no difference was observed in Zhongyan 100. In most cases, sole and low NO3- nutrition impaired the elongation and formation of first-order lateral roots (1 degrees LRs), only in NC89, thus reducing the root growth. IAA concentration and DR5::GUS expression levels decreased in roots when NC89 was subjected to sole and low NO3- nutrition media, suggesting that different NH4+/NO3- ratios affect the transport of auxin from leaves to roots. Results were similar following exogenous NAA application to low NO3- nutrition treated seedlings. Based on direct [H-3]IAA transport measurement, the transport of polar auxin from shoots to roots decreased due to low NO3- nutrition. PIN4 expression levels were markedly decreased in roots of NC89 by sole and low NO3- nutrition, while they were unaffected in Zhongyan 100 roots. Overall, our findings suggest that LRs formation in tobacco seedlings is regulated by NH4+/NO3- ratios via modifying polar transport of auxin.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序