Auxin biosynthetic gene TAR2 is involved in low nitrogen-mediated reprogramming of root architecture in Arabidopsis.
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.
The State Key Laboratory for Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Wenying
W
Ma
Jingjuan
J
Li
Baoyuan
B
Qu
Xue
X
He
Xueqiang
X
Zhao
Bin
B
Li
Xiangdong
X
Fu
Yiping
Y
Tong
D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D009928:Organ Specificity; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D058526:Plant Vascular Bundle / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D051279:Tryptophan Transaminase / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C000593373:TAR2 protein, Arabidopsis; D051279:Tryptophan Transaminase; D009584:Nitrogen
Arabidopsis thaliana; TAR2; auxin biosynthesis; lateral root; low nitrogen stress