A nuclear-located RNA Helicase 13 is essential for chloroplast development in Arabidopsis thaliana.

Chloroplast is a semi-autonomous organelle with a double membrane structure, and its structural stability is the prerequisite for its correct function. Chloroplast development is regulated by known nuclear-encoded chloroplast proteins or proteins encoded within the chloroplast itself. However, the mechanism of chloroplast development is involved in other organelles remains largely unknown. Here, we report that a nuclear-located DEAD-box RNA helicase 13 (RH13) is essential for chloroplast development in Arabidopsis thaliana. RH13 is widely expressed in tissues and localized to the nucleolus. Homozygous rh13 mutant shows abnormal chloroplast structure and leaf morphogenesis. Proteomic analysis shows that the expression levels of photosynthesis related proteins in chloroplasts are reduced due to loss of RH13. Furthermore, RNA-sequencing and proteomics data reveals that the expression levels of these chloroplast-related genes are decreased which undergo alternative splicing events in rh13 mutant. Taken together, we propose that nucleolus-located RH13 is critical for chloroplast development in Arabidopsis.