Mapping and Candidate Gene Analysis of the Low-Temperature-Sensitive Albino Gene in Rice Seedlings.

Chloroplasts are organelles responsible for photosynthesis in plants, providing energy for growth and development. However, the genetic regulatory mechanisms underlying early chloroplast development in rice remain incompletely understood. In this study, we identified a rice seedling thermosensitive chlorophyll-deficient mutant, , and the genetic analysis of two F populations suggested that this trait may be controlled by more than one pair of alleles. Through reciprocal F populations and QTL-seq technology, was mapped to the interval of 24,280,402-25,920,942 bp on rice chromosome 8, representing a novel albino gene in rice. Within the candidate gene region of , there were 258 predicted genes, among which , , and encode pentatricopeptide repeat (PPR) proteins. RNA-seq identified 18 DEGs (differentially expressed genes) within the candidate interval, with showing homology to the pigment biosynthesis-related genes and ; and were implicated in chlorophyll precursor synthesis. RT-qPCR was employed to assess the expression levels of , , , , , and in the wild-type and mutant plants. Among them, the differences in the expression levels of and were the most significant. This study will contribute to further elucidating the molecular mechanisms of rice chloroplast development.