Auxin biosynthetic gene TAR2 is involved in low nitrogen-mediated reprogramming of root architecture in Arabidopsis
Auxin biosynthetic gene TAR2 is involved in low nitrogen-mediated reprogramming of root architecture in Arabidopsis
复制标题
生长素生物合成基因 TAR2 参与拟南芥低氮介导的根结构重编程
DOI：
10.1111/tpj.12448
复制
发表时间：
2014-04-01
期刊：
影响因子：
7.2
通讯作者：
Tong, Yiping
中科院分区：
文献类型：
--
作者：
Ma, Wenying;Li, Jingjuan;Tong, Yiping
在植物中，根系结构对氮可用性的可塑性在很大程度上决定了氮的获取效率。根系生长对低氮利用率的一种鲜为人知的反应是观察到侧根（LR）数量和长度的增加。在这里，我们表明低氮诱导的拟南芥 LR 生长取决于生长素生物合成基因 TAR2（色氨酸转氨酶相关 2）的功能。 TAR2在中柱鞘和靠近根尖的成熟根区的维管系统中表达，并在低氮条件下被诱导。在野生型植物中，低氮刺激生长素在具有超过三层细胞层和LR出苗的非出苗LR原基中积累。相反，这些低氮介导的生长素积累和根生长反应在 tar2-c 无效突变体中受到损害。 TAR2 的过表达在高氮和低氮条件下均增加了 LR 数量。我们的结果表明，TAR2 是响应低氮条件而重新编程根结构所必需的。这一发现提出了一种通过根部 TAR2 表达工程来提高氮利用效率的新策略。
In plants, the plasticity of root architecture in response to nitrogen availability largely determines nitrogen acquisition efficiency. One poorly understood root growth response to low nitrogen availability is an observed increase in the number and length of lateral roots (LRs). Here, we show that low nitrogen-induced Arabidopsis LR growth depends on the function of the auxin biosynthesis gene TAR2 (tryptophan aminotransferase related 2). TAR2 was expressed in the pericycle and the vasculature of the mature root zone near the root tip, and was induced under low nitrogen conditions. In wild type plants, low nitrogen stimulated auxin accumulation in the non-emerged LR primordia with more than three cell layers and LR emergence. Conversely, these low nitrogen-mediated auxin accumulation and root growth responses were impaired in the tar2-c null mutant. Overexpression of TAR2 increased LR numbers under both high and low nitrogen conditions. Our results suggested that TAR2 is required for reprogramming root architecture in response to low nitrogen conditions. This finding suggests a new strategy for improving nitrogen use efficiency through the engineering of TAR2 expression in roots.