TSC1 enables plastid development under dark conditions, contributing to rice adaptation to transplantation shock

Abstract

Since its domestication from wild rice thousands of years ago, rice has been cultivated largely through transplantation. During transplantation from the nursery to the paddy field, rice seedlings experience transplantation shock which affects their physiology and production. However, the mechanisms underlying transplantation shock and rice adaptation to this shock are largely unknown. Here, we isolated a transplant-sensitive chloroplast-deficient (tsc1) rice mutant that produces albino leaves after transplantation. Blocking light from reaching the juvenile leaves and leaf primordia caused chloroplast deficiencies in transplanted tsc1 seedlings. TSC1 encodes a noncanonical adenosine triphosphate-binding cassette (ABC) transporter homologous to AtNAP14 and is of cyanobacterial origin. We demonstrate that TSC1 controls plastid development in rice under dark conditions, and functions independently of light signaling. However, light rescued the tsc1 mutant phenotype in a spectrum-independent manner. TSC1 was upregulated following transplantation, and modulated the iron and copper levels, thereby regulating prolamellar body formation during the early P4 stage of leaf development. Therefore, TSC1 is indispensable for plastid development in the absence of light, and contributes to adaptation to transplantation shock. Our study provides insight into the regulation of plastid development and establishes a framework for improving recovery from transplantation shock in rice.

A rice chloroplast‐localized ABC transporter ARG1 modulates cobalt and nickel homeostasis and contributes to photosynthetic capacity

“…3g). Knockout of OsABCI8 was recently shown to result in an albino‐revertible phenotype under continuous rainy day conditions and after transplantation (Zeng et al ., 2017; Shi et al ., 2018). Thus, the subcellular localization, protein interaction and the albino phenotype of these knockout mutants support the view that OsABCI7 and/or OsABCI8 probably function as CbiO components in rice.…”

FRUCTOKINASE‐LIKE PROTEIN 1 interacts with TRXz to regulate chloroplast development in rice

“…In addition to these chloroplast biogenesis factors characterized in other plant species, several genes involved in PEP‐related chloroplast development have been identified in rice (Gong et al ; Wang et al , , ; Shi et al ). WSL3/OspTAC3 encodes a SAP protein that performs a necessary role for early chloroplast biogenesis by interacting with TAC complex components, such as OspTAC2, OspTAC10, OsFSD3, OspTAC12, OspTAC14, and OsTRXz (Wang et al ).…”

Plastid caseinolytic protease OsClpR1 regulates chloroplast development and chloroplast RNA editing in rice

“…Leaf color is one of the important factors affecting photosynthesis, which directly affects rice yield. To date, more than 120 genes have been reported to regulate chloroplast development in rice, such as YGL8 , TSC1 , and Lhca4 (Kong et al 2016 ; Shi et al 2018 ; Yamatani et al 2018 ). The expression levels of chlorophyll biosynthesis and plastid-encoded genes in the al3 mutant were remarkably reduced compared with the wild type (Additional file 1 : Figure S3).…”