Comprehensive Profiling of Tubby-Like Proteins in Soybean and Roles of the GmTLP8 Gene in Abiotic Stress Responses

Abstract

Tubby-like proteins (TLPs) are transcription factors that are widely present in eukaryotes and generally participate in growth and developmental processes. Using genome databases, a total of 22 putative TLP genes were identified in the soybean genome, and unevenly distributed across 13 chromosomes. Phylogenetic analysis demonstrated that the predicted GmTLP proteins were divided into five groups (I-V). Gene structure, protein motifs, and conserved domains were analyzed to identify differences and common features among the GmTLPs. A three-dimensional protein model was built to show the typical structure of TLPs. Analysis of publicly available gene expression data showed that GmTLP genes were differentially expressed in response to abiotic stresses. Based on those data, GmTLP8 was selected to further explore the role of TLPs in soybean drought and salt stress responses. GmTLP8 overexpressors had improved tolerance to drought and salt stresses, whereas the opposite was true of GmTLP8-RNAi lines. 3,3-diaminobenzidine and nitro blue tetrazolium staining and physiological indexes also showed that overexpression of GmTLP8 enhanced the tolerance of soybean to drought and salt stresses; in addition, downstream stress-responsive genes were upregulated in response to drought and salt stresses. This study provides new insights into the function of GmTLPs in response to abiotic stresses.

Genome-wide identification and comprehensive analysis of tubby-like protein gene family in multiple crops

“…A typical TLP, containing the conserved tubby domain formed with a β-barrel structure consisting of one α-helix and 12 anti-parallel strands, functions as a bipartite transcription regulator ( Carroll et al., 2004 ). In addition to be identified in mice ( Kleyn et al., 1996 ), human ( North et al., 1997 ) and other animals ( Heikenwalder et al., 2001 ; Figlewicz et al., 2004 ), this family was also identified in plants such as rice ( Kou et al., 2009 ), Arabidopsis ( Lai et al., 2004 ), wheat ( Hong et al., 2015 ; Li et al., 2018 ; An et al., 2019 ), apple ( Xu et al., 2016 ), soybean ( Xu et al., 2022 ) and cassava ( Dong et al., 2019 ). The widespread and high conservation of tubby family in eukaryotes suggested the fundamental function of growth and development in animals and plants ( Carroll et al., 2004 ; Wang et al., 2018 ; Devane et al., 2022 ).…”

Genome-Wide Identification, Characterization, and Expression Analysis of Tubby-like Protein (TLP) Gene Family Members in Woodland Strawberry (Fragaria vesca)

“…In this study, we identified eight TLP s in woodland strawberry ( F. vesca ). The number of TLP s was significantly less in woodland strawberry than in other diploid plants, such as Arabidopsis (11), rice (14), poplar (11), maize (15), tomato (11), and soybean (22) [ 11 , 15 , 23 , 35 ], and no paired paralogous TLP genes were identified in F. vesca ( Figure 1 ) as has been observed in TLP s in Arabidopsis , rice, and poplar [ 35 ]. Intron/exon structures provide important insights into the evolutionary relationships among members of gene families [ 36 ].…”

“…TLPs have been reported to play important roles in the response to abiotic stress in chickpea, apple, cotton, tomato, cucumber, and soybean [ 15 , 19 , 20 , 22 , 25 , 26 ]. FvTLP s also play a role in the response to multiple types of stress and hormone treatments.…”

“…OsTLP2 might activate disease resistance pathways by regulating the expression of OsWRKY13 [ 8 ]. In annual Medicago species, barley, maize, cassava, apple, cotton, soybean, wheat, and Salvia miltiorrhiza , the expression of TLP s is affected by various abiotic stresses and hormone treatments [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. TLP1 , TLP3 , and TLP5 were identified as potential candidate genes for functional studies in cotton because of their putative functions in drought and salt stress responses [ 18 ].…”

“…AtTLP11 might affect seed development by modulating NHL6 expression [ 27 ], and AtTLP2 regulates the biosynthesis of homogalacturonan, the major polysaccharides constituent of the Arabidopsis seed coat mucilage, by activating UDP-glucose 4-epimerase 1 (UGE1) [ 28 ]. GmTLP8 confers abiotic stress tolerance in plants via stress-responsive genes [ 15 ]. ScTLP12 might contribute to the rolling of leaves in rye [ 29 ].…”