biostudies-literatureQiu ZNatural Science Foundation of Shandong of China50https://www.ebi.ac.uk/biostudies/studies/S-EPMC9547768biostudies-literatureUnknown15(1)WHIRLY (WHY) family proteins, a small family of single-stranded DNA (ssDNA) binding proteins, are widely found in plants and have multiple functions to regulate plant growth and development. However, WHY in rice has received less attention. In this study, we continued our previous study on OsTRX z that is important for chloroplast development. OsTRX z was discovered to interact with OsWHY1, which was confirmed using yeast two-hybrid, pull-down, and BiFC assays. Subsequently, the oswhy1 mutants were obtained by CRISPR/Cas9, which exhibited an albino phenotype and died after the three-leaf stage. Consistent with this albino phenotype, low amounts of Chl a, Chl b, and Car were detected in the oswhy1-1 mutant. Moreover, the oswhy1-1 mutant had chloroplasts with disrupted architecture and no stRice (New York, N.Y.)OsWHY1 Interacts with OsTRX z and is Essential for Early Chloroplast Development in Rice.PMC9547768ZR2020QC111Qiu ZZeng QZhu LYu GGuan PSong JChen DTeng LZhang PfalseOsWHY1 Interacts with OsTRX z and is Essential for Early Chloroplast Development in Rice.WHIRLY (WHY) family proteins, a small family of single-stranded DNA (ssDNA) binding proteins, are widely found in plants and have multiple functions to regulate plant growth and development. However, WHY in rice has received less attention. In this study, we continued our previous study on OsTRX z that is important for chloroplast development. OsTRX z was discovered to interact with OsWHY1, which was confirmed using yeast two-hybrid, pull-down, and BiFC assays. Subsequently, the oswhy1 mutants were obtained by CRISPR/Cas9, which exhibited an albino phenotype and died after the three-leaf stage. Consistent with this albino phenotype, low amounts of Chl a, Chl b, and Car were detected in the oswhy1-1 mutant. Moreover, the oswhy1-1 mutant had chloroplasts with disrupted architecture and no st2022-01-01T00:00:00Z2022 Oct2025-04-19T06:38:49.27Z2025-04-19T06:38:49.27ZS-EPMC95477683620837110.1186/s12284-022-00596-y