ETHYLENE-INSENSITIVE 3-LIKE 2 regulates β-carotene and ascorbic acid accumulation in tomatoes during ripening

Abstract

ETHYLENE-INSENSITIVE 3/ETHYLENE-INSENSITIVE 3-LIKEs (EIN3/EILs) are important ethylene response factors during fruit ripening. Here, we discovered that EIL2 controls carotenoid metabolism and ascorbic acid (AsA) biosynthesis in tomato (Solanum lycopersicum). In contrast to the red fruits presented in the wild type (WT) 45 days after pollination, the fruits of CRISPR/Cas9 eil2 mutants and SlEIL2 RNAi lines (ERIs) showed yellow or orange fruits. Correlation analysis of transcriptome and metabolome data for the ERI and WT ripe fruits revealed that SlEIL2 is involved in β-carotene and AsA accumulation. ETHYLENE RESPONSE FACTORs (ERFs) are the typical components downstream from EIN3 in the ethylene response pathway. Through a comprehensive screening of ERF family members, we determined that SlEIL2 directly regulates the expression of four SlERFs. Two of these, SlERF.H30 and SlERF.G6, encode proteins that participate in the regulation of LYCOPENE-β-CYCLASE 2 (SlLCYB2), encoding an enzyme that mediates the conversion of lycopene to carotene in fruits. In addition, SlEIL2 transcriptionally repressed L-GALACTOSE 1-PHOSPHATE PHOSPHATASE 3 (SlGPP3) and MYO-INOSITOL OXYGENASE 1 (SlMIOX1) expression, which resulted in 1.62 fold increase of AsA via both the L-galactose and myoinositol pathways. Overall, we demonstrated that SlEIL2 functions in controlling β-carotene and AsA levels, providing a potential strategy for genetic engineering to improve the nutritional value and quality of tomato fruit.

Integrated analysis of metabolome, transcriptome, and bioclimatic factors of Acer truncatum seeds reveals key candidate genes related to unsaturated fatty acid biosynthesis, and potentially optimal production area

“…ETHYLENE-INSENSITIVE 3/ETHYLENE-INSENSITIVE 3-LIKEs (EIN3/EILs) are important ethylene response factors during fruit ripening. Correlation analysis of transcriptome and metabolome data revealed that EIL2 is involved in β-carotene and ascorbic acid accumulation in tomato ( Solanum lycopersicum ), which could provide a future in strategy genetic engineering to improve the nutritional value and quality of tomato fruit [ 25 ]. Combined transcriptomic and metabolomic analysis between the staminate and pistillate flowers of mulberry revealed that DEGs and DMs may be associated with sex differentiation of mulberry through the regulation of the enrichment pathways, such as the MAPK pathway, which provides a rich source for the analysis of the molecular mechanism of mulberry sex differentiation processes [ 26 ].…”

The EIN3 transcription factor GmEIL1 improves soybean resistance to Phytophthora sojae

“…EIN3 and EIL proteins can directly bind to the promoters of target genes to activate their transcription in plant growth and development processes as well as in response to biotic and abiotic stresses (Chen et al., 2023 ; Dolgikh et al., 2019 ; Peng et al., 2014 ; Wang, Xu, et al., 2019 ; Zhang et al., 2011 ). In Hevea brasiliensis , potential HbEIN3 target genes were identified, including latex biosynthesis and drainage‐related genes (Wang, Xu, et al., 2019 ).…”

Ethylene Signaling Pathway Genes in Strawberry and Their Expression Patterns during Fruit Ripening

“…It has been reported that ETR genes seem to be more responsive in younger strawberries than in older ones during fruit ripening, since they showed a great expression increase between stages large green and white [35]. EIN3/EINs belong to a small family of transcription factors that activate the downstream components (ethylene-responsive factors and other downstream genes) of the ethylene signaling pathway [58][59][60]. Specific FaEIN3/EINs showed high expression levels at the initial red stage of the strawberry fruit in a certain cultivar, suggesting they might play a role during fruit ripening.…”