Barley young leaf chlorina, a putative pentatricopeptide repeat gene, is essential for chloroplast development in young leaves.

A spontaneous barley mutant, young leaf chlorina (ylc), was identified in this study. Young leaves of ylc exhibited a yellow base and green tip, with reduced chlorophyll content, and altered chlorophyll fluorescence pattern, and underdeveloped grana in chloroplasts. The color of mutant leaves gradually transitioned to pale green and then became green in mature leaves.