High-throughput discovery of plastid genes causing albino phenotypes in ornamental chimeric plants
Authors and Affiliations
Authors and Affiliations
Hyun-Seung Park1,2,†, Jae-Hyeon Jeon1,†, Woohyeon Cho1,†, Yeonjeong Lee1,†, Jee Young Park1, Jiseok Kim1, Young Sang Park1, Hyun Jo Koo1, Jung Hwa Kang3, Taek Joo Lee3, Sang Hoon Kim4, Jin-Baek Kim4, Hae-Yun Kwon5, Suk-Hwan Kim1, Nam-Chon Paek1, Geupil Jang6, Jeong-Yong Suh7 and Tae-Jin Yang1,*
1Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
2Department of Integrative Biological Sciences and Industry, Sejong University, Seoul 05006, Korea
3Hantaek Botanical Garden, Yongin, Gyeonggi-do, 17183, Republic of Korea
4Radiation Breeding Research Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Korea
5Special Forest Resources Division, National Institute of Forest Science, Suwon 16631, Korea
6School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
7Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
†These four authors contributed equally
Hyun-Seung Park, Jae-Hyeon Jeon, Woohyeon Cho and Yeonjeong Lee, These four authors contributed equally.
*Corresponding author: Tae-Jin Yang
Chimeric plants composed of green and albino tissues have great ornamental value. To unveil the functional genes responsible for albino phenotypes in chimeric plants, we inspected the complete plastid genomes (plastomes) in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species, including monocots, dicots, and gymnosperms. In nine chimeric plants, plastomes were identical between green and albino tissues. Meanwhile, another 14 chimeric plants were heteroplasmic, showing a mutation between green and albino tissues. We identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase (rpo) or photosystems which caused albinism in the chimeric plants. Among them, 12 were deleterious mutations in the target genes, in which early termination appeared due to small deletion-mediated frameshift or single nucleotide substitution. Another was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 gene. We inspected chlorophyll structure, protein functional model of the rpoC2, and expression levels of the related genes in green and albino tissues of Reynoutria japonica. A single amino acid change, histidine-to-proline substitution, in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase, impairing the biosynthesis of the photosynthesis system in the albino tissue of R. japonica chimera plant.