Comprehensive Genome-Wide Analysis of Thaumatin-Like Gene Family in Four Cotton Species and Functional Identification of GhTLP19 Involved in Regulating Tolerance to Verticillium dahlia and Drought

Abstract

Thaumatin-like proteins (TLPs) present in the form of large multigene families play important roles in biotic stress and abiotic stress. However, there has been no systematic analysis of the TLPs in cotton. In this study, comprehensive identification and evolutionary analysis of TLPs in four species of cotton were conducted. In total, 50, 48, 91, and 90 homologous sequences were identified in Gossypium raimondii, G. arboreum, G. barbadense, and G. hirsutum, respectively. Gene structure, protein motifs, and gene expression were further investigated. Transcriptome and quantitative real-time PCR analysis indicated that GhTLPs participate in abiotic, biotic stress and cotton fiber development. GhTLP19 on chromosome At05 was selected as a candidate gene for further study. When GhTLP19 was silenced by virus-induced gene silencing (VIGS) in cotton, with the increase of malondialdehyde (MDA) content and the decrease of catalase (CAT) content, and as the increase of disease index (DI) and hyphae accumulation, the plants were more sensitive to drought and Verticillium dahliae. Furthermore, the GhTLP19 overexpressing Arabidopsis transgenic lines exhibited higher proline content, thicker and longer trichomes and more tolerance to drought when compared to wild type. This study will provide a basis and reference for future research on their roles in stress tolerance and fiber development.

Molecular characterization revealed the role of thaumatin-like proteins in stress response in bread wheat

“…Further, the expression profiling of TLPs under various tissues and developmental stages also advocated the putative involvement of these genes in development of vegetative and reproductive tissues. Similar expression trend in various plant tissues and their role in reproductive tissues like flowers and seeds has also been reported in earlier studies, for instance, TLP genes in Gossypium hirsutum, also showed their varied expression pattern in vegetative as well as in reproductive organs [18,56,71]. The role of TLP genes in fungal resistance has been reported in earlier studies against numerous pathogens including Fusarium sp.…”

“…Expression analysis of genes is a significant way to understand their involvement in various developmental and physiological processes. Previously, TLPs are reported to be involved in plant growth and developmental processes [56,57]. Therefore, we performed the expression analysis of TLPs under various tissues and their developmental stages.…”

“…The role of TLP genes in fungal resistance has been reported in earlier studies against numerous pathogens including Fusarium sp. [72], Microdochium nivale [73], Rhizoctonia solani [74] and Verticillium dahlia [56] in wheat and other plant species. The differential expression of TaTLP genes in response to Pst and Bgt infestation further established their roles in fungal stress responses.…”

“…Moreover, similar to our finding's differential expression and upregulation of TLP genes at various hours of drought, salt and cold stress treatment has also been reported in other plants like Brassica rapa and Gossypium sp. [56,75]. Further, the over-expression of TLP genes provided increased tolerance against various abiotic stresses in tobacco, cotton, Arabidopsis etc.…”

Molecular Identification and Antifungal Properties of Four Thaumatin-like Proteins in Spruce (Picea likiangensis)

“…Over-expression of the PeTLP gene in transgenic poplars showed enhanced resistance against Marssonina brunnea [23]. In addition, some TLP genes have also been reported to confer tolerance to abiotic stresses such as drought, salt, and low temperatures in transgenic plants [17,21,24,25].…”