Cucumber NUCLEAR FACTOR-YC2/-YC9 target translocon component CsTIC21 in chloroplast photomorphogenesis

Abstract

Light signals promote photomorphogenesis and photosynthesis, allowing plants to establish photoautotrophic growth. Chloroplasts are organelles responsible for photosynthesis in which light energy is converted into chemical energy and stored as organic matter. However, how light regulates chloroplast photomorphogenesis remains unclear. Here, we isolated a cucumber (Cucumis sativus L.) mutant albino seedling (as) from an ethyl methane sulfonate mutagenesis (EMS) library with an albino phenotype. Map-based cloning revealed that the mutation occurred in a component of cucumber Translocon at Inner membrane of Chloroplasts (CsTIC21). Subsequently, Virus-Induced Gene Silencing (VIGS) and CRISPR/Cas9 analyses confirmed the association between the mutant gene and the as phenotype. Loss-of-function of CsTIC21 induces malformation of chloroplast formation, leading to albinism and death in cucumber. Notably, CsTIC21 transcription was very low in etiolated seedlings grown in the dark and was up-regulated by light, with expression patterns similar to those of Nuclear Factor-YC (NF-YC) genes. Here, seven cucumber NF-YC family genes (CsNF-YC) were identified, among which the expression of four genes (CsNF-YC1, -YC2, -YC9, and -YC13) responded to light. Gene silencing of all CsNF-YC genes in cucumber indicated that CsNF-YC2, -YC9, -YC11-1, and -YC11-2 induced distinct etiolated growth and decreased chlorophyll content. Interaction studies verified that CsNF-YC2 and CsNF-YC9 target the CsTIC21 promoter directly and promote gene transcription. These findings provide mechanistic insights on the role of the NF-YCs–TIC21 module in chloroplast photomorphogenesis promoted by light in cucumber.

Genome-wide identification and expression analysis of NF-Y gene family in tobacco (Nicotiana tabacum L.)

“…Therefore, NtNF-YC3 and NtNF-YC16 may be potential candidate genes for regulating photomorphogenesis. In addition, studies have shown that CsNF-YC2 and CsNF-YC9 were involved in chloroplast photomorphogenesis in cucumber, and a CsNF-YC2/-YC9-CsTIC21 model was proposed 46 .…”

“…Therefore, NtNF-YC3 and NtNF-YC16 may be potential candidate genes for regulating photomorphogenesis. In addition, studies have shown that CsNF-YC2 and CsNF-YC9 were involved in chloroplast photomorphogenesis in cucumber, and a CsNF-YC2/-YC9-CsTIC21 model was proposed 46 . Many studies have found that NF-Y transcription factors play an important role in plant growth and development and abiotic stress 13 .…”

Rapid Construction and Application of a Vector for Tobacco Ringspot Virus-Induced McPDS Silencing in Bitter Gourd

“…This induces the target mRNA to degrade or change its methylation, which stops the target gene from being translated normally [8]. Using VIGS technology, researchers can quickly figure out the function of a target gene by comparing the number of its downregulated transcripts to changes in the plant's biochemistry and physiology [1][2][3][4][5][6][7][8][9][10][11]. This method does not require stable genetic transformation, and it is easy to use when aiming to study gene functions in a short amount of time and at a low cost [12,13].…”