The FtsH-Inactive Protein FtsHi5 Is Required for Chloroplast Development and Protein Accumulation in Chloroplasts at Low Ambient Temperature in Arabidopsis

Abstract

Chloroplasts are indispensable for higher plants. The growth and development of plants are very sensitive to environmental temperature changes, and chloroplast development is also regulated by adverse environmental temperatures. However, the molecular mechanism of how plants coordinate chloroplast development and environmental temperature changes remains largely unknown. Here, a temperature-conditioned chloroplast development defective mutant thermo-sensitive mutant in leaf color 2 (tsl2) of Arabidopsis was obtained through a forward genetic screening. The tsl2 mutant showed a weak yellowish phenotype at normal growth temperature (22°C), and the phenotype was more pronounced at low growth temperature (16°C) and largely rescued at high growth temperature (29°C). Bulk Segregant Analysis (BSA) revealed that TSL2 encodes FtsH-Inactive Protein 5 (FtsHi5). Genetic complementation analysis confirmed that complemented expression of FtsHi5 rescued the chlorophyll content and thylakoid development defects observed in tsl2 mutants at 16°C. Quantitative mass spectrometry analysis with Tandem Mass Tag (TMT) isobaric labeling revealed broad changes in the chloroplast proteome of tsl2 mutant plants at low temperature, which is agreed with the impaired chloroplast biogenesis and function in tsl2 plants. Together, our data demonstrates that FtsHi5/TSL2 plays an important role in chloroplast development and protein accumulation in chloroplasts, especially at low environmental temperatures in Arabidopsis.

Physiological, Photosynthetic, and Transcriptomics Insights into the Influence of Shading on Leafy Sweet Potato

“…Chlorophyll levels fluctuated significantly under low-light environments, as their biosynthesis required the participation of catalytic enzyme genes, such as CHLI and PPOX, which were highly expressed in the present study [74,75]. Other DEGs related to chloroplast development and Chlorophyll synthesis were also collected, such as DCL, RPL21c, DAG, SG1, FtsHi5, and Tic110 [76][77][78][79][80][81]. Furthermore, the introns-splicing-related DEGs, such as PPRs, CFM3, MTERF4, and MTERF5, were also upregulated in this study.…”

Genomic divergence between two sister Medicago species triggered by the quaternary climatic oscillations on the Qinghai–Tibet plateau and northern China

“…The identified genes may be related to environmental conditions (i.e., response to high altitude, drought and salinity) and reproductive divergence (e.g., pollen tube growth and flowering) between the two species (Table S7). For example, among significantly divergent genes with selection signatures, we found four ( GRF4 , PSUT , FTSHI and PIF1 ) related to cold response (Jiang et al, 2020; Lantzouni et al, 2020; Li et al, 2022; Patzke et al, 2019) and six ( RAD23C , CHR24 , ALY3 , RECQ4A , RAD7 and BSD ) associated with nucleotide excision‐repair and DNA‐damage tolerance (Hacker et al, 2022; Kunz et al, 2005; Lahari et al, 2018; Lang et al, 2021; Shaked et al, 2006). These genes may be important for the adaptation of M. archiducis‐nicolai to high‐altitude environments.…”

“…The identified genes may be related to environmental conditions (i.e., response to high altitude, drought and salinity) and reproductive divergence (e.g., pollen tube growth and flowering) between the two species (Table S7). For example, among significantly divergent genes with selection signatures, we found four (GRF4, PSUT, FTSHI and PIF1) related to cold response (Jiang et al, 2020;Lantzouni et al, 2020;Li et al, 2022;Patzke et al, 2019) and six (RAD23C, CHR24, ALY3, RECQ4A, RAD7…”

Chloroplast proteostasis: A story of birth, life, and death

“…Interestingly, a recent study showed that Tic236, a large TIC component constantly linking the TIC and TOC complex, also plays a role in chloroplast division ( Chen et al., 2018b ; Fang et al., 2022 ), providing a hint for the connection of these two processes. The depletion of FtsHi5 results in hypersensitivity to decreased ambient temperature ( Li et al., 2021 ), which has also been observed in many mutants with disrupted chloroplast proteostasis ( fug1 , prps17 , prpl11 , and var2 ; Marino et al., 2019 ), indicating a close link between chloroplast proteostasis and temperature stress.…”