AUTHOR=He Xin , Solis Celymar A. , Chavan Sachin G. , Maier Chelsea , Wang Yuanyuan , Liang Weiguang , Klause Norbert , Ghannoum Oula , Cazzonelli Christopher I. , Tissue David T. , Chen Zhong-Hua 

TITLE=Novel transcriptome networks are associated with adaptation of capsicum fruit development to a light-blocking glasshouse film

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1280314

DOI=10.3389/fpls.2023.1280314

ISSN=1664-462X

ABSTRACT=<p>Light-blocking films (LBFs) can contribute to significant energy savings for protected cropping via altering light transmitting, such as UVA, photosynthetically active radiation, blue and red spectra affecting photosynthesis, and capsicum yield. Here, we investigated the effects of LBF on orange color capsicum (O06614, <italic>Capsicum annuum</italic> L.) fruit transcriptome at 35 (mature green) and 65 (mature ripe) days after pollination (DAP) relative to untreated control in a high-technology glasshouse. The results of targeted metabolites showed that LBF significantly promotes the percentage of lutein but decreased the percentage of zeaxanthin and neoxanthin only at 35 DAP. At 35 DAP, fruits were less impacted by LBF treatment (versus control) with a total of 1,192 differentially expressed genes (DEGs) compared with that at 65 DAP with 2,654 DEGs. Response to stress and response to light stimulus in biological process of Gene Ontology were found in 65-DAP fruits under LBF vs. control, and clustering analysis revealed a predominant role of light receptors and phytohormone signaling transduction as well as starch and sucrose metabolism in LBF adaptation. The light-signaling DEGs, UV light receptor <italic>UVR8</italic>, transcription factors <italic>phytochrome-interacting factor 4</italic> (<italic>PIF4</italic>), and an <italic>E3 ubiquitin ligase</italic> (<italic>COP1</italic>) were significantly downregulated at 65 DAP. Moreover, key DEGs in starch and sucrose metabolism (<italic>SUS</italic>, <italic>SUC</italic>, and <italic>INV</italic>), carotenoid synthesis (<italic>PSY2</italic> and <italic>BCH1</italic>), ascorbic acid biosynthesis (<italic>VTC2</italic>, <italic>AAO</italic>, and <italic>GME</italic>), abscisic acid (ABA) signaling (<italic>NCED3</italic>, <italic>ABA2</italic>, <italic>AO4</italic>, and <italic>PYL2/4</italic>), and phenylpropanoid biosynthesis (<italic>PAL</italic> and <italic>DFR</italic>) are important for the adaptation of 65-DAP fruits to LBF. Our results provide new candidate genes for improving quality traits of low-light adaptation of capsicum in protected cropping.</p>