Chitosan induces jasmonic acid production leading to resistance of ripened fruit against Botrytis cinerea infection.

Chitosan can function a key role in plant resistant against Botrytis cinerea infection, while its mechanism is unclear in ripened fruits. In this study, we investigated the chitosan effect on two type of ripened fruits including strawberry and grapes (Kyoho and Shine-Muscat) when were infected with B. cinerea. Results showed that chitosan inhibited B. cinerea growth, increased phenolic compounds and cell wall composition, modulated oxidative stress and induced jasmonic acid (JA) production in ripened fruits. Data-independent acquisition (DIA) showed that 224 and 171 proteins were upregulated 1.5-fold by chitosan in Kyoho and Shine-Muscat grape, respectively. Topless-related protein 3 (TPR3) were identified and interacted with histone deacetylase 19 (HDAC19) and negatively regulated by JA and chitosan. Meanwhile, overexpression of VvTPR3 and VvHDAC19 reduced the stability of cell wall against B. cinerea in strawberry. Taken together, chitosan induces defense related genes and protect the fruit quality against Botrytis infection through JA signaling.

Genome-wide identification, evolution, and molecular characterization of the PP2C gene family in woodland strawberry.

The protein phosphatase 2C (PP2C) gene family is one of the momentous and conserved plant-specific gene families, known to participate in cellular processes via reversible protein phosphorylation and regulates signal transduction in eukaryotic organisms. Recently, PP2Cs were identified in Arabidopsis and maize, however, the whole-genome analysis of PP2C in strawberry has not yet been reported. In the current research, we found 62 PP2C-encoding genes in total from the strawberry genome. Further, the phylogenetic analysis categorized FvPP2C genes into twelve subgroups with significant structural conservation based on conserved domain and amino acid sequence. Moreover, we observed a strong signature of purifying selection between the comparison of orthologous gene pairs of strawberry and Arabidopsis. The comparison of RNA-sequence (RNA-seq) data published on various vegetative and reproductive tissues of strawberry plant suggested the significant role of FvPP2C genes in organ development. The qRT-PCR validation of thirty FvPP2C genes indicated their critical tolerance-related role under abiotic stress stimuli in strawberry. Finally, the subcellular localization of FvPP2C51 gene proves that it resides and stimulates its function in the nucleus. Our findings provide an overview of the identification of strawberry FvPP2C gene family and demonstrate their critical role in tissue-specific response and abiotic stress-tolerance, thereby, intimating their significance in the strawberry molecular breeding for the resistant cultivars.

Characterization and Identification of PpEIN3 during the Modulation of Fruit Ripening Process by Ectopic Expressions in Tomato.

CORE IDEAS: First study of PpEIN3 by transgenic experiments to verify its function in the maturity process PpEIN3 is a positive regulator of ethylene signal transduction pathway to promote fruits ripening Ethylene is one of the most important phytohormone in plants and plays a critical role during growth, development, maturity, and aging. The framework of the ethylene signaling pathway is well reported. Nevertheless, studies on Ethylene Insensitive 3 (EIN3), the downstream regulator of the ethylene signaling pathway, need to be investigated, especially in peach [Prunus persica (L.) Batsch]. In this study, we cloned PpEIN3 from peach and characterized it in tomato (Solanum lycopersicum L.). Our results depicted that the open-reading frame of PpEIN3 was 1875 bp, encoding a protein with 624 amino acid residues that contained a conserved EIN3 domain, a highly conserved N-terminal region, and seven DNA-binding sites. PpEIN3 showed very close association with homologous EIN genes from apple (Malus domestica Borkh.) and grapevine (Vitis vinifera L.). All investigated EIN proteins shared similar domains and structures. The PpEIN3 promoter possessed several motifs related to hormones that affect fruit development and ripening. Spatial-temporal expression analysis revealed that PpEIN3 was expressed at high levels in the late stage of fruit development vs. the early stage. In transgenic tomato, PpEIIN3 showed overexpression and the key ethylene biosynthesis genes SlACO1, SlACS1, and SlSAMS1 were upregulated and promoted early maturation in fruit. By contrast, PpEIIN3 silencing delayed ripening and reduced SlEIN3 expression in tomato. The results confirmed that PpEIN3 is a positive regulator of the ethylene signal transduction pathway, which promoted fruit ripening. Our findings provide valuable insight to the roles in ethylene signal components in the modulation of peach fruit ripening.