GSE161358
SHORT-ROOT 1 is critical to cell division and tracheary element development in rice roots
The exocyst is a key factor in vesicle transport and is involved in cell secretion, cell growth, cell division, and other cytological processes in eukaryotes. EXO70 is the key exocyst subunit. We obtained a mutant SHORT-ROOT gene, SR1, through map-based cloning and genetic complementation. SR1 encodes a plant-conserved protein with an EXO70 domain. SR1 mutation affected the whole root-development process, producing shorter radicles, adventitious roots, and lateral roots, abnormal xylem development, causing dwarfing, and decreasing the water potential and moisture content. SR1 was largely expressed in the roots, but only in developing root meristems and tracheary elements. The shortness of the sr1 mutant roots was caused by the presence of fewer meristem cells. The in situ histone H4 expression patterns confirmed that cell proliferation during root development was impaired. Tracheary element dysplasia was caused by marked decreases in the inner diameters of and distances between the perforations of adjacent tracheary elements. The membrane transport of the sr1 mutants was blocked, affecting cell division in the root apical region and root tracheary element development. The study of SR1 will improve our understanding of the function of the EXO70 gene in rice and guide future studies on the molecular mechanisms involved in plant root development. Overall design: Development of two rice transcriptome sequencing and analysis software RNAseq