OsSPL3, an SBP-Domain Protein, Regulates Crown Root Development in Rice
OsSPL3, an SBP-Domain Protein, Regulates Crown Root Development in Rice
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OsSPL3 是一种 SBP 结构域蛋白，调节水稻冠根的发育
DOI：
10.1105/tpc.19.00038
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发表时间：
2019-06-01
期刊：
影响因子：
11.6
通讯作者：
Mao, Chuanzao
中科院分区：
文献类型：
--
作者：
Shao, Yanlin;Zhou, Hong-Zhu;Mao, Chuanzao
谷物的主要根系由冠根（或不定根）组成，它对植物在土壤中的锚定以及对水分和养分的吸收很重要。然而，冠根形成的分子基础在很大程度上是未知的。本研究从水稻（Oryza sativa）中分离出一个冠根较少的突变体，命名为低冠根数1 （lcrn1）。基于图谱的克隆表明，lcrn1是由一个假定的转录因子编码基因——O. sativa SQUAMOSA PROMOTER BINDING PROTEIN-LIKE3 （OsSPL3）突变引起的。我们证明lcrn1的点突变会干扰theO。sativa microRNA156 （OsmiR156）定向切割OsSPL3转录本，导致突变表型。对OsSPL3结合位点的染色质免疫沉淀测序和lcrn1中差异表达转录物的RNA测序进一步确定了OsSPL3在基底淋巴结的潜在直接靶点，包括MADS-box转录因子OsMADS50。过表达OsMADS50的植株产生较少的冠根，表型复制lcrn1，而在lcrn1背景下敲除OsMADS50逆转了这种表型。我们还发现OsmiR156的另一个靶基因OsSPL12调控OsMADS50和冠根发育。综上所述，我们的研究结果表明，OsmiR156-OsSPL3/OsSPL12模块可以直接激活水稻节点中的OsMADS50来调节水稻冠根的发育。
The major root system of cereals consists of crown roots (or adventitious roots), which are important for anchoring plants in the soil and for water and nutrient uptake. However, the molecular basis of crown root formation is largely unknown. Here, we isolated a rice (Oryza sativa) mutant with fewer crown roots, named lower crown root number1 (lcrn1). Map-based cloning revealed that lcrn1 is caused by a mutation of a putative transcription factor-coding gene, O. sativa SQUAMOSA PROMOTER BINDING PROTEIN-LIKE3 (OsSPL3). We demonstrate that the point mutation in lcrn1 perturbs theO. sativa microRNA156 (OsmiR156)-directed cleavage of OsSPL3 transcripts, resulting in the mutant phenotype. Chromatin immunoprecipitation sequencing assays of OsSPL3 binding sites and RNA sequencing of differentially expressed transcripts in lcrn1 further identified potential direct targets of OsSPL3 in basal nodes, including a MADS-box transcription factor, OsMADS50. OsMADS50-overexpressing plants produced fewer crown roots, phenocopying lcrn1, while knocking out OsMADS50 in the lcrn1 background reversed this phenotype. We also show that OsSPL12, another OsmiR156 target gene, regulates OsMADS50 and crown root development. Taken together, our findings suggest a novel regulatory pathway in which the OsmiR156-OsSPL3/OsSPL12 module directly activates OsMADS50 in the node to regulate crown root development in rice.