scholarly journals Genome-Wide Identification of Chitinase Genes in Thalassiosira Pseudonana and Analysis of Their Expression Under Abiotic Stresses

Author(s):  
Haomiao Cheng ◽  
Zhanru Shao ◽  
Chang Lu ◽  
Delin Duan

Abstract Background: The nitrogen-containing polysaccharide chitin is the second most abundant biopolymer on earth and is found in the cell walls of diatoms, where it serves as a scaffold for biosilica deposition. Diatom chitin is an important source of carbon and nitrogen in the marine environment, but surprisingly little is known about basic chitinase metabolism in diatoms.Results: Here, we identify and fully characterize 24 chitinase genes from the model centric diatom Thalassiosira pseudonana. We demonstrate that their expression is broadly upregulated under abiotic stresses, despite the fact that chitinase activity itself remains unchanged, and we discuss several explanations for this result. We also examine the potential transcriptional complexity of the intron-rich T. pseudonana chitinase genes and provide evidence for two separate tandem duplication events during their evolution.Conclusions: Given the many applications of chitin and chitin derivatives in suture production, wound healing, drug delivery, and other processes, new insight into diatom chitin metabolism has both theoretical and practical value.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Haomiao Cheng ◽  
Zhanru Shao ◽  
Chang Lu ◽  
Delin Duan

Abstract Background The nitrogen-containing polysaccharide chitin is the second most abundant biopolymer on earth and is found in the cell walls of diatoms, where it serves as a scaffold for biosilica deposition. Diatom chitin is an important source of carbon and nitrogen in the marine environment, but surprisingly little is known about basic chitinase metabolism in diatoms. Results Here, we identify and fully characterize 24 chitinase genes from the model centric diatom Thalassiosira pseudonana. We demonstrate that their expression is broadly upregulated under abiotic stresses, despite the fact that chitinase activity itself remains unchanged, and we discuss several explanations for this result. We also examine the potential transcriptional complexity of the intron-rich T. pseudonana chitinase genes and provide evidence for two separate tandem duplication events during their evolution. Conclusions Given the many applications of chitin and chitin derivatives in suture production, wound healing, drug delivery, and other processes, new insight into diatom chitin metabolism has both theoretical and practical value.


2021 ◽  
Vol 7 (11) ◽  
pp. 895
Author(s):  
Rehab Abdelmonem Mohamed ◽  
Kang Ren ◽  
Ya-Ni Mou ◽  
Sheng-Hua Ying ◽  
Ming-Guang Feng

Carbon catabolite repression (CCR) is critical for the preferential utilization of glucose derived from environmental carbon sources and regulated by carbon catabolite repressor A (Cre1/CreA) in filamentous fungi. However, a role of Cre1-mediated CCR in insect-pathogenic fungal utilization of host nutrients during normal cuticle infection (NCI) and hemocoel colonization remains explored insufficiently. Here, we report an indispensability of Cre1 for Beauveria bassiana’s utilization of nutrients in insect integument and hemocoel. Deletion of cre1 resulted in severe defects in radial growth on various media, hypersensitivity to oxidative stress, abolished pathogenicity via NCI or intrahemocoel injection (cuticle-bypassing infection) but no change in conidial hydrophobicity and adherence to insect cuticle. Markedly reduced biomass accumulation in the Δcre1 cultures was directly causative of severe defect in aerial conidiation and reduced secretion of various cuticle-degrading enzymes. The majority (1117) of 1881 dysregulated genes identified from the Δcre1 versus wild-type cultures were significantly downregulated, leading to substantial repression of many enriched function terms and pathways, particularly those involved in carbon and nitrogen metabolisms, cuticle degradation, antioxidant response, cellular transport and homeostasis, and direct/indirect gene mediation. These findings offer a novel insight into profound effect of Cre1 on the insect-pathogenic lifestyle of B. bassiana.


Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1389
Author(s):  
Xiqiang Liu ◽  
Han Zhang ◽  
Lin Ma ◽  
Zan Wang ◽  
Kun Wang

The trihelix transcription factor (GT) family is widely involved in regulating plant growth and development, and most importantly, responding to various abiotic stresses. Our study first reported the genome-wide identification and analysis of GT family genes in Medicago truncatula. Overall, 38 trihelix genes were identified in the M. truncatula genome and were classified into five subfamilies (GT-1, GT-2, SH4, GTγ and SIP1). We systematically analyzed the phylogenetic relationship, chromosomal distribution, tandem and segmental duplication events, gene structures and conserved motifs of MtGTs. Syntenic analysis revealed that trihelix family genes in M. truncatula had the most collinearity relationship with those in soybean followed by alfalfa, but very little collinearity with those in the maize and rice. Additionally, tissue-specific expression analysis of trihelix family genes suggested that they played various roles in the growth and development of specific tissues in M. truncatula. Moreover, the expression of some MtGT genes, such as MtGT19, MtGT20, MtGT22, and MtGT33, was dramatically induced by drought, salt, and ABA treatments, illustrating their vital roles in response to abiotic stresses. These findings are helpful for improving the comprehensive understanding of trihelix family; additionally, the study provides candidate genes for achieving the genetic improvement of stress resistance in legumes.


2022 ◽  
Vol 23 (1) ◽  
pp. 515
Author(s):  
Hui Wei ◽  
Ali Movahedi ◽  
Guoyuan Liu ◽  
Yixin Li ◽  
Shiwei Liu ◽  
...  

Poplar is an illustrious industrial woody plant with rapid growth, providing a range of materials, and having simple post-treatment. Various kinds of environmental stresses limit its output. Plant annexin (ANN) is a calcium-dependent phospholipid-binding protein involved in plant metabolism, growth and development, and cooperatively regulating drought resistance, salt tolerance, and various stress responses. However, the features of the PtANN gene family and different stress responses remain unknown in poplar. This study identified 12 PtANN genes in the P. trichocarpa whole-genome and PtANNs divided into three subfamilies based on the phylogenetic tree. The PtANNs clustered into the same clade shared similar gene structures and conserved motifs. The 12 PtANN genes were located in ten chromosomes, and segmental duplication events were illustrated as the main duplication method. Additionally, the PtANN4 homogenous with AtANN1 was detected localized in the cytoplasm and plasma membrane. In addition, expression levels of PtANNs were induced by multiple abiotic stresses, which indicated that PtANNs could widely participate in response to abiotic stress. These results revealed the molecular evolution of PtANNs and their profiles in response to abiotic stress.


2021 ◽  
Author(s):  
Yu Fan ◽  
Jun Yan ◽  
Dili Lai ◽  
Hao Yang ◽  
Guoxing Xue ◽  
...  

Abstract Background: GRAS is a very important family of transcription factors that are unique to plants, playing important roles in plant development and their response to abiotic stress. Since the sequencing of the sorghum genome, a large number of genetic studies based on this genomic information have been carried out. Nevertheless, no detailed identification or genome-wide analysis of GRAS family genes in Sorghum bicolor has been published.Results: A total of 81 SbGRAS genes were identified based on the S. bicolor genome. They were named SbGRAS01 to SbGRAS81 and grouped into 13 subfamilies (LISCL, DLT, OS19, SCL4/7, PAT1, SHR, SCL3, HAM-1, SCR, DELLA, HAM-2, LAS and OS4). SbGRAS genes are not evenly distributed on the chromosomes, and we found tandem duplication events and segmental duplications of SbGRAS genes on S. bicolor chromosomes. According to the results of the gene and motif composition, SbGRAS members located in the same group contained analogous intron/exon and motif organizations. By quantitative (q) RT-PCR, we quantified the expression of SbGRAS members in different plant tissues and in plants exposed to six abiotic stresses at the seedling stage. We also measured gibberellin content under the different abiotic stresses.Conclusions: We identified 81 SbGRAS genes and further analyzed their structural composition, and evolution and expression patterns of SbGRAS proteins. The latter analysis indicated that SbGRAS is important in the course of plant development and its response to abiotic stress. Collectively, this systematic analysis lays the foundation for further study of the functional characteristics of GRAS genes of S. bicolor.


Sexualities ◽  
2020 ◽  
pp. 136346072098169
Author(s):  
Aidan McKearney

This article focuses on the experiences of gay men in the rural west and northwest region of Ireland, during a period of transformational social and political change in Irish society. These changes have helped facilitate new forms of LGBTQI visibility, and local radicalism in the region. Same-sex weddings, establishment of rural LGBT groups and marching under an LGBT banner at St Patricks Day parades would have been unthinkable in the recent past; but they are now becoming a reality. The men report continuing challenges in their lives as gay men in the nonmetropolitan space, but the emergence of new visibility, voice and cultural acceptance of LGBT people is helping change their lived experiences. The study demonstrates the impact of local activist LGBT citizens. Through their testimonies we can gain an insight into the many, varied and interwoven factors that have interplayed to create the conditions necessary for the men to: increasingly define themselves as gay to greater numbers of people in their localities; to embrace greater visibility and eschew strategies of silence; and aspire to a host of legal, political, cultural and social rights including same-sex marriage. Organic forms of visibility and local radicalism have emerged in the region and through an analysis of their testimonies we can see how the men continue to be transformed by an ever-changing landscape.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Lingling DOU ◽  
Limin LV ◽  
Yangyang KANG ◽  
Ruijie TIAN ◽  
Deqing HUANG ◽  
...  

Abstract Background Calmodulin (CaM) is one of the most important Ca2+ signaling receptors because it regulates diverse physiological and biochemical reactions in plants. CaM functions by interacting with CaM-binding proteins (CaMBPs) to modulate Ca2+ signaling. IQ domain (IQD) proteins are plant-specific CaMBPs that bind to CaM by their specific CaM binding sites. Results In this study, we identified 102 GhIQD genes in the Gossypium hirsutum L. genome. The GhIQD gene family was classified into four clusters (I, II, III, and IV), and we then mapped the GhIQD genes to the G. hirsutum L. chromosomes. Moreover, we found that 100 of the 102 GhIQD genes resulted from segmental duplication events, indicating that segmental duplication is the main force driving GhIQD gene expansion. Gene expression pattern analysis showed that a total of 89 GhIQD genes expressed in the elongation stage and second cell wall biosynthesis stage of the fiber cells, suggesting that GhIQD genes may contribute to fiber cell development in cotton. In addition, we found that 20 selected GhIQD genes were highly expressed in various tissues. Exogenous application of MeJA significantly enhanced the expression levels of GhIQD genes. Conclusions Our study shows that GhIQD genes are involved in fiber cell development in cotton and are also widely induced by MeJA. Thw results provide bases to systematically characterize the evolution and biological functions of GhIQD genes, as well as clues to breed better cotton varieties in the future.


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