Overexpression of E3 Ubiquitin Ligase Gene AdBiL Contributes to Resistance against Chilling Stress and Leaf Mold Disease in Tomato

Abstract

Ubiquitination is a common regulatory mechanism, playing a critical role in diverse cellular and developmental processes in eukaryotes. However, a few reports on the functional correlation between E3 ubiquitin ligases and reactive oxygen species (ROS) or reactive nitrogen species (RNS) metabolism in response to stress are currently available in plants. In the present study, the E3 ubiquitin ligase gene AdBiL (Adi3 Binding E3 Ligase) was introduced into tomato line Ailsa Craig via Agrobacterium-mediated method. Transgenic lines were confirmed for integration into the tomato genome using PCR. Transcription of AdBiL in various transgenic lines was determined using real-time PCR. Evaluation of stress tolerance showed that T1 generation of transgenic tomato lines showed only mild symptoms of chilling injury as evident by higher biomass accumulation and chlorophyll content than those of non-transformed plants. Compared with wild-type plants, the contents of AsA, AsA/DHA, GSH and the activity of GaILDH, γ-GCS and GSNOR were increased, while H2O2, O2.−, MDA, NO, SNOs, and GSNO accumulations were significantly decreased in AdBiL overexpressing plants in response to chilling stress. Furthermore, transgenic tomato plants overexpressing AdBiL showed higher activities of enzymes such as G6PDH, 6PGDH, NADP-ICDH, and NADP-ME involved in pentose phosphate pathway (PPP). The transgenic tomato plants also exhibited an enhanced tolerance against the necrotrophic fungus Cladosporium fulvum. Tyrosine nitration protein was activated in the plants infected with leaf mold disease, while the inhibition could be recovered in AdBiL gene overexpressing lines. Taken together, our results revealed a possible physiological role of AdBiL in the activation of the key enzymes of AsA–GSH cycle, PPP and down-regulation of GSNO reductase, thereby reducing oxidative and nitrosative stress in plants. This study demonstrates an optimized transgenic strategy using AdBiL gene for crop improvement against biotic and abiotic stress factors.

Identification of microRNAs associated with the exogenous spermidine-mediated improvement of high-temperature tolerance in cucumber seedlings (Cucumis sativus L.)

“…Many of these target genes were involved in the ubiquitin-proteasome pathway (UPP), including E3 ubiquitin ligase enzymes (F-box family protein, ring finger protein and U-box protein) and the 26S proteasome. E3 ubiquitin ligases play an important role in regulating the plant response to abiotic stress by regulating the abundance of critical stress-responsive transcription factors [ 49 , 50 ]. In our study, miR6475 was down-regulated under high-temperature stress and up-regulated after exogenous Spd treatment.…”

Expression Patterns and Functional Analysis of 11 E3 Ubiquitin Ligase Genes in Rice

“…First, E3 ubiquitin ligases are involved in response to biotic stresses. The ATL subfamily that contains the conserved RING-H2 domain is activated by the elicitor and plays important roles in disease resistance, possibly through the regulation of the elicitor-signaling pathway, including chitin ( Serrano and Guzman, 2004 ; Berrocal-Lobo et al, 2010 ; Ni et al, 2010 ; Chen et al, 2017 ; Deng et al, 2017 ). The U-box domain family of E3 ubiquitin ligases also plays important roles in defense response.…”

Overexpression of tomato RING E3 ubiquitin ligase gene SlRING1 confers cadmium tolerance by attenuating cadmium accumulation and oxidative stress

“…In particular, ubiquitination of proteins is a major type of post‐translational modification, through which, one or more small protein molecules called ubiquitin (Ub) are bound to the substrate proteins, followed by degradation of the ubiquitinated proteins via the ubiquitin‐proteasome system (UPS) (Di Giacomo et al, 2013; Hasan et al, 2017; Yu et al, 2020). UPS‐mediated protein degradation is vital for cellular protein homeostasis, protein quality control system, and plant‐environment interactions (Chen et al, 2017; Hasan et al, 2017; Lyzenga & Stone, 2012; Sadanandom et al, 2012; Yu et al, 2016). Ubiquitination also controls the abundance of regulatory proteins through the UPS (Stone, 2019; Zhang et al, 2015).…”