AUTHOR=He Fang , Shi Yu-Jie , Chen Qi , Li Jun-Lin , Niu Meng-Xue , Feng Cong-Hua , Lu Meng-Meng , Tian Fei-Fei , Zhang Fan , Lin Tian-Tian , Chen Liang-Hua , Liu Qin-lin , Wan Xue-Qin 

TITLE=Genome-Wide Investigation of the PtrCHLP Family Reveals That PtrCHLP3 Actively Mediates Poplar Growth and Development by Regulating Photosynthesis

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.870970

DOI=10.3389/fpls.2022.870970

ISSN=1664-462X

ABSTRACT=<p>Chlorophyll (Chl) plays a crucial role in plant photosynthesis. The geranylgeraniol reductase gene (<italic>CHLP</italic>) participates in the terminal hydrogenation of chlorophyll biosynthesis. Although there are many studies related to the genome-wide analysis of <italic>Populus trichocarpa</italic>, little research has been conducted on <italic>CHLP</italic> family genes, especially those concerning growth and photosynthesis. In this study, three <italic>CHLP</italic> genes were identified in <italic>Populus</italic>. The evolutionary tree indicated that the <italic>CHLP</italic> family genes were divided into six groups. Moreover, one pair of genes was derived from segmental duplications in <italic>Populus</italic>. Many elements related to growth were detected by <italic>cis</italic>-acting element analysis of the promoters of diverse <italic>PtrCHLPs</italic>. Furthermore, <italic>PtrCHLPs</italic> exhibit different tissue expression patterns. In addition, <italic>PtrCHLP3</italic> is preferentially expressed in the leaves and plays an important role in regulating chlorophyll biosynthesis. Silencing of <italic>PtrCHLP3</italic> in poplar resulted in a decrease in chlorophyll synthesis in plants, thus blocking electron transport during photosynthesis. Furthermore, inhibition of <italic>PtrCHLP3</italic> expression in poplar can inhibit plant growth through the downregulation of photosynthesis. Ultimately, <italic>PtrCHLP3</italic> formed a co-expression network with photosynthesis and chlorophyll biosynthesis-related genes, which synergistically affected the growth and photosynthesis of poplars. Thus, this study provides genetic resources for the improved breeding of fast-growing tree traits.</p>