Genome-wide analysis of Myo-inositol oxygenase gene family in tomato reveals their involvement in ascorbic acid accumulation

Abstract

Background Ascorbic acid (Vitamin C, AsA) is an antioxidant metabolite involved in plant development and environmental stimuli. AsA biosynthesis has been well studied in plants, and MIOX is a critical enzyme in plants AsA biosynthesis pathway. However, Myo-inositol oxygenase (MIOX) gene family members and their involvement in AsA biosynthesis and response to abiotic stress remain unclear. Results In this study, five tomato genes encoding MIOX proteins and possessing MIOX motifs were identified. Structural analysis and distribution mapping showed that 5 MIOX genes contain different intron/exon patterns and unevenly distributed among four chromosomes. Besides, expression analyses indicated the remarkable expression of SlMIOX genes in different plant tissues. Furthermore, transgenic lines were obtained by over-expression of the MIOX4 gene in tomato. The overexpression lines showed a significant increase in total ascorbate in leaves and red fruits compared to control. Expression analysis revealed that increased accumulation of AsA in MIOX4 overexpression lines is possible as a consequence of the multiple genes involved in AsA biosynthesis. Myo inositol (MI) feeding in leaf and fruit implied that the Myo-inositol pathway improved the AsA biosynthesis in leaves and fruits. MIOX4 overexpression lines exhibited abetter light response, abiotic stress tolerance, and AsA biosynthesis capacity. Conclusions These results showed that MIOX4 transgenic lines contribute to AsA biosynthesis, evident as better light response and improved oxidative stress tolerance. This study provides the first comprehensive analysis of the MIOX gene family and their involvement in ascorbate biosynthesis in tomato.

Enhanced resistance to heat and fungal infection in transgenic Trichoderma via over-expressing the HSP70 gene

“…The thermal tolerance of organisms has been identified as a complex multi-genic trait that involves multiple physiological and biochemical mechanisms and requires the coordinated and precise activation of numerous genes (Sun et al 2021 ; Pudake et al 2017 ). However, previous studies on different species, including animals, plants and microorganisms, have shown that over-expressing a single HSP70 effectively improves thermal stability (D’Souza et al 2022 ; Ni et al 2021 ; Montero-Barrientos et al 2010 ). In our study, transgenic Tv-1511 strains over-expressing TvHSP70 exhibited significant growth advantages and maintained an improved growth-promoting ability compared with WT strains under heat stress.…”

“…In addition, several genes involved in glutathione (Yamazaki et al 2019 ), carotenoid (Yu and Tian. 2021 ), ascorbate (Munir et al 2020 ), unsaturated fatty acid biosynthesis (Xue et al 2020 ) and phenylalanine metabolism (Xu and Zhang. 2020 ) were significantly activated in the transgenic strains.…”

Plant–herbivore interactions: Experimental demonstration of genetic variability in plant–plant signalling

“…No gene was found at the first SNP on the second chromosome, but this SNP was upstream to AT2G19800, a gene that encodes a myo-inositol oxygenase (MIOX). MIOX gene family is involved in oxidative stress tolerance (Munir et al, 2020). On the fourth chromosome, a significant SNP was located in AT4G27080, a gene that encodes a disulphide isomerase-like (PDIL) protein (Table S1), involved in biotic and abiotic stress tolerance (Chen et al, 2012;Wang et al, 2019).…”

Структурно-Функциональный Анализ Генов-Гомологов Gme1 И Накопление Аскорбата В Плодах У Культурных И Дикорастущих Видов Томата

“…Возможное объяснение в дополнение к сформулированному выше предположению, что транскрипционная активность гена GME1 может влиять на содержание аскорбата в плодах на стадиях, предшествующих полной зрелости, состоит в том, что GME1, помимо биосинтеза аскорбата, активно вовлечен в синтез клеточной стенки во время роста плода (38). Также следует учитывать, что помимо L-галактозного пути, для образования аскорбата в плодах томата могут быть использованы другие альтернативные пути биосинтеза, например мио-инозитольный (39).…”