PHOTO-SENSITIVE LEAF ROLLING 1 encodes a polygalacturonase
Guangheng Zhang+, Xin Hou+ , Li Wang+ , Jing Xu , Jian Chen , Xue Fu ,Nianwei Shen , JinqiangNian , Zhuanzhuan Jiang , JiangHu， Li Zhu , Yuchun Rao , Yafei Shi ，Deyong Ren , Guojun Dong，ZhenyuGao , LongbiaoGuo , Qian Qian* and Sheng Luan*
New Phytologist
10.1111/nph.16899
Abstract
The biosynthesis and modification of cell wall composition and structure are controlled by
hundreds of enzymes and have a direct consequence on plant growth and development.
However, the majority of these enzymes has not been functionally characterised.
Rice mutants with leaf-rolling phenotypes were screened in a field. Phenotypic analysis
under controlled conditions was performed for the selected mutant and the relevant gene
was identified by map-based cloning. Cell wall composition was analysed by glycome profiling
assay.
We identified a photo-sensitive leaf rolling 1 (psl1) mutant with ‘napping’ (midday depression
of photosynthesis) phenotype and reduced growth. The PSL1 gene encodes a cell walllocalised
polygalacturonase (PG), a pectin-degrading enzyme. psl1 with a 260-bp deletion in
its gene displayed leaf rolling in response to high light intensity and/or low humidity. Biochemical
assays revealed PG activity of recombinant PSL1 protein. Significant modifications to
cell wall composition in the psl1 mutant compared with the wild-type plants were identified.
Such modifications enhanced drought tolerance of the mutant plants by reducing water loss
under osmotic stress and drought conditions.
Taken together, PSL1 functions as a PG that modifies cell wall biosynthesis, plant development
and drought tolerance in rice.