title: Functional and RNA-Sequencing Analysis Revealed Expression of a Novel Stay-Green Gene fromZoysia japonica(ZjSGR) Caused Chlorophyll Degradation and Accelerated Senescence in Arabidopsis.
abstract: Senescence is not only an important developmental process, but also a responsive regulation to abiotic and biotic stress for plants. Stay-green protein plays crucial roles in plant senescence and chlorophyll degradation. However, the underlying mechanisms were not well-studied, particularly in non-model plants. In this study, a novel stay-green gene,ZjSGR, was isolated fromZoysia japonica. Subcellular localization result demonstrated that ZjSGR was localized in the chloroplasts. Quantitative real-time PCR results together with promoter activity determination using transgenic Arabidopsis confirmed thatZjSGRcould be induced by darkness, ABA and MeJA. Its expression levels could also be up-regulated by natural senescence, but suppressed by SA treatments. Overexpression ofZjSGRin Arabidopsis resulted in a rapid yellowing phenotype; complementary experiments proved thatZjSGRwas a functional homolog ofAtNYE1fromArabidopsis thaliana. Over expression ofZjSGRaccelerated chlorophyll degradation and impaired photosynthesis in Arabidopsis. Transmission electron microscopy observation revealed that overexpression ofZjSGRdecomposed the chloroplasts structure. RNA sequencing analysis showed thatZjSGRcould play multiple roles in senescence and chlorophyll degradation by regulating hormone signal transduction and the expression of a large number of senescence and environmental stress related genes. Our study provides a better understanding of the roles ofSGRs, and new insight into the senescence and chlorophyll degradation mechanisms in plants.
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Teng
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Chang
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Crop Growth Regulation of Hebei Province, Agricultural University of Hebei Baoding, China.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Sun
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liang
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Xu
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Yuehui
authors.initials: Y
authors.lastname: Chao
authors.affiliation: Turfgrass Research Institute, Beijing Forestry University Beijing, China.
authors.forename: Liebao
authors.initials: L
authors.lastname: Han
keywords: RNA sequencing; SGRs; Zoysia japonica; chlorophyll degradation; senescence