Abstract: The OsSP1 gene encodes a chloroplast localized protein in rice, and its expression clearly responds to drought stress.In order to elucidate the effect of OsSP1 gene on rice growth and drought stress tolerance, OsSP1 gene-edited and overexpressed rice plants were created by using CRISPR/Cas9 gene editing technology and gene overexpression technology, respectively. The mutation pattern of OsSP1 gene in the gene-edited plants was determined by sequencing analysis, and homozygous overexpression plants were selected by hpt sequence detection and hygromycin B screening assay. The results of phenotypic comparison, chlorophyll content and reactive oxygen species(ROS) determination and drought tolerance analysis showed that overexpression of OsSP1 gene in rice had almost no effect on rice growth and drought stress tolerance. However, after the OsSP1 gene was mutated through gene editing, the growth and fruiting of rice T₀ and T₁ gene-edited plants were severely affected with biallelic heterozygous or homozygous mutations, and all showed severe growth inhibition such as dwarf, etiolation, premature aging, and non-tillering, T₀ plants produced very few seeds, while the T₁ plants did not head at all, and the chlorophyll content in leaf of the gene-edited plants was significantly or extremely significantly lower than that of the wild-type and overexpressed plants. These results indicated the essential role of OsSP1 gene in rice growth and yield, and provided a theoretical and material basis for elucidating the underlying mechanism of OsSP1 gene in rice.

Key words: Rice, OsSP1, Gene editing, Overexpression, Growth, Drought tolerance

CLC Number: 

• S511.03

• Q78