scholarly journals The cDNA Structures and Expression Profile of the Ascorbate Peroxidase Gene Family During Drought Stress in Wild Watermelon

2018 ◽  
Vol 10 (8) ◽  
pp. 56
Author(s):  
Goitseone Malambane ◽  
Hisashi Tsujimoto ◽  
Kinya Akashi

Ascorbate peroxidase (APX) plays an important role in detoxifying reactive oxygen species under environmental stress. Although previous work in drought-tolerant wild watermelon has shown an increase in chloroplast APX enzyme activity under drought, molecular entities of APX have remained uncharacterized. In this study, structure and transcriptional regulation of the APX gene family in watermelon were characterized. Five APX genes, designated as CLAPX1 to CLAPX5, were identified from watermelon genome. The mRNA alternative splicing was suggested for CLAPX5, which generated two distinct deduced amino acid sequences at their C-terminus, in resemblance to a reported alternative splicing of chloroplast APXs in pumpkin. This observation suggests that two isoenzymes for stromal and thylakoid-bound APXs may be generated from the CLAPX5 gene. Phylogenetic analysis classified CLAPX isoenzymes into three clades, i.e., chloroplast, microbody, and cytosolic. Physiological analyses of wild watermelon under drought showed a decline in stomatal conductance and CO2 assimilation rate, and a significant increase in the enzyme activities of both chloroplast and cytosolic APXs. Profiles of mRNA abundance during drought were markedly different among CLAPX genes, suggesting distinct transcriptional regulation for the APX isoenzymes. Up-regulation of CLAPX5-I and CLAPX5-II was observed at the early phase of drought stress, which was temporally correlated with the observed increase in chloroplast APX enzyme activity, suggesting that transcriptional up-regulation of the CLAPX5 gene may contribute to the fortification of chloroplast APX activity under drought. Our study has provided an insight into the functional significance of the CLAPX gene family in the drought tolerance mechanism in this plant.

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e84203 ◽  
Author(s):  
Mohamed Zouine ◽  
Yongyao Fu ◽  
Anne-Laure Chateigner-Boutin ◽  
Isabelle Mila ◽  
Pierre Frasse ◽  
...  

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 111 ◽  
Author(s):  
Roger Holmes ◽  
Keri Barron ◽  
Natalia Krupenko

Ceramide synthase 6 (CerS6, also known as LASS6) is one of the six members of ceramide synthase gene family in humans. Comparisons of CerS6 amino acid sequences and structures as well as of CerS6 gene structures/locations were conducted using data from several vertebrate genome projects. A specific role for the CerS6 gene and protein has been identified as the endoplasmic reticulum C14- and C16-ceramide synthase. Mammalian CerS6 proteins share 90–100% similarity among different species, but are only 22–63% similar to other CerS family members, suggesting that CerS6 is a distinct gene family. Sequence alignments, predicted transmembrane, lumenal and cytoplasmic segments and N-glycosylation sites were also investigated, resulting in identification of the key conserved residues, including the active site as well as C-terminus acidic and serine residues. Mammalian CerS6 genes contain ten exons, are primarily located on the positive strands and transcribed as two major isoforms. The human CERS6 gene promoter harbors a large CpG island (94 CpGs) and multiple transcription factor binding sites (TFBS), which support precise transcriptional regulation and signaling functions. Additional regulation is conferred by 15 microRNA (miRNA) target sites identified in the CERS6 3′-UTR region. Phylogenetic analysis of the vertebrate CerS1–6 gene families relationships supports a major role for the CerS6 enzyme that is strongly conserved throughout vertebrate evolution.


Open Biology ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200141
Author(s):  
Ying Huang ◽  
Xin Huang ◽  
Xuming Zhou ◽  
Jialin Wang ◽  
Ruidong Zhang ◽  
...  

Genomic regions with repeated sequences are unstable and prone to rapid DNA diversification. However, the role of tandem repeats within the coding region is not fully characterized. Here, we have identified a new hypervariable C-type lectin gene family with different numbers of tandem repeats (Rlecs; R means repeat) in oriental river prawn ( Macrobrachium nipponense ) . Two types of repeat units (33 or 30 bp) are identified in the second exon, and the number of repeat units vary from 1 to 9. Rlecs can be classified into 15 types through phylogenetic analysis. The amino acid sequences in the same type of Rlec are highly conservative outside the repeat regions. The main differences among the Rlec types are evident in exon 5. A variable number of tandem repeats in Rlecs may be produced by slip mispairing during gene replication. Alternative splicing contributes to the multiplicity of forms in this lectin gene family, and different types of Rlecs vary in terms of tissue distribution, expression quantity and response to bacterial challenge. These variations suggest that Rlecs have functional diversity. The results of experiments on sugar binding, microbial inhibition and clearance, regulation of antimicrobial peptide gene expression and prophenoloxidase activation indicate that the function of Rlecs with the motif of YRSKDD in innate immunity is enhanced when the number of tandem repeats increases. Our results suggest that Rlecs undergo gene expansion through gene duplication and alternative splicing, which ultimately leads to functional diversity.


2020 ◽  
Author(s):  
Shichao Sun ◽  
Xianpeng Xiong ◽  
Xiaoli Zhang ◽  
Hongjie Feng ◽  
Qianhao Zhu ◽  
...  

Abstract Background: The function of 4-coumarate-CoA ligases (4CL) under abiotic stresses has been studied in plants, however, limited is known about the 4CL genes in cotton (G. hirsutum L.) and their roles in response to drought stress.Results: We performed genome-wide identification of the 4CL genes in G. hirsutum and investigated the expression profiles of the identified genes in various cotton tissues and in response to stress conditions with an aim to identify 4CL gene(s) associated with drought tolerance. We identified 34 putative 4CL genes in G. hirsutum that were clustered into three classes. Genes of the same class usually share a similar gene structure and motif composition. Many cis-elements related to stress and phytohormone responses were found in the promoters of the Gh4CL genes. Of the 34 Gh4CL genes, 26 were induced by at least one abiotic stress and 10 (including Gh4CL7) were up-regulated under the polyethylene glycol (PEG) simulated drought stress conditions. Virus-induced gene silencing (VIGS) in cotton and overexpression (OE) in Arabidopsis thaliana were applied to investigate the biological function of Gh4CL7 in drought tolerance. The Gh4CL7-silencing cotton plants showed more sensitive to drought stress, probably due to decreased relative water content (RWC), chlorophyll content and antioxidative enzyme activity, increased stomatal aperture, and the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2). Arabidopsis lines overexpressing Gh4CL7, however, were more tolerant to drought treatment, which was associated with improved antioxidative enzyme activity, reduced accumulation of MDA and H2O2 and up-regulated stress-related genes under the drought stress conditions. In addition, compared to their respective controls, the Gh4CL7-silencing cotton plants and the Gh4CL7-overexpressing Arabidopsis lines had a ~20% reduction and a ~10% increase in lignin content, respectively. The expression levels of genes related to lignin biosynthesis, including PAL, CCoAOMT, COMT, CCR and CAD, were lower in Gh4CL7-silencing plants than in controls. Taken together, these results demonstrated that Gh4CL7 could positively respond to drought stress and therefore might be a candidate gene for improvement of drought tolerance in cotton.Conclusion: We characterized the 4CL gene family in upland cotton and revealed a role of Gh4CL7 in lignin biosynthesis and drought tolerance.


2019 ◽  
Vol 52 (1) ◽  
Author(s):  
Subhan Danish ◽  
Muhammad Zafar-Ul-Hye ◽  
Shahid Hussain ◽  
Muhammad Riaz ◽  
Muhammad Farooq Qayyum

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1534
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Chandrakant Tiwari ◽  
Shalini Purwar ◽  
Mukul Kumar ◽  
...  

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Teame Gereziher MEHARI ◽  
Yanchao XU ◽  
Richard Odongo MAGWANGA ◽  
Muhammad Jawad UMER ◽  
Joy Nyangasi KIRUNGU ◽  
...  

Abstract Background Cotton is an important commercial crop for being a valuable source of natural fiber. Its production has undergone a sharp decline because of abiotic stresses, etc. Drought is one of the major abiotic stress causing significant yield losses in cotton. However, plants have evolved self-defense mechanisms to cope abiotic factors like drought, salt, cold, etc. The evolution of stress responsive transcription factors such as the trihelix, a nodule-inception-like protein (NLP), and the late embryogenesis abundant proteins have shown positive response in the resistance improvement to several abiotic stresses. Results Genome wide identification and characterization of the effects of Light-Harvesting Chloro a/b binding (LHC) genes were carried out in cotton under drought stress conditions. A hundred and nine proteins encoded by the LHC genes were found in the cotton genome, with 55, 27, and 27 genes found to be distributed in Gossypium hirsutum, G. arboreum, and G. raimondii, respectively. The proteins encoded by the genes were unevenly distributed on various chromosomes. The Ka/Ks (Non-synonymous substitution rate/Synonymous substitution rate) values were less than one, an indication of negative selection of the gene family. Differential expressions of genes showed that majority of the genes are being highly upregulated in the roots as compared with leaves and stem tissues. Most genes were found to be highly expressed in MR-85, a relative drought tolerant germplasm. Conclusion The results provide proofs of the possible role of the LHC genes in improving drought stress tolerance, and can be explored by cotton breeders in releasing a more drought tolerant cotton varieties.


Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Priyanka Dwivedi ◽  
Naleeni Ramawat ◽  
Gaurav Dhawan ◽  
Subbaiyan Gopala Krishnan ◽  
Kunnummal Kurungara Vinod ◽  
...  

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.


Author(s):  
Nils Stührwohldt ◽  
Eric Bühler ◽  
Margret Sauter ◽  
Andreas Schaller

Abstract Increasing drought stress poses a severe threat to agricultural productivity. Plants, however, evolved numerous mechanisms to cope with such environmental stress. Here we report that the stress-induced production of a peptide signal contributes to stress tolerance. The expression of phytosulfokine (PSK) peptide precursor genes, and transcripts of three subtilisin-like serine proteases, SBT1.4, SBT3.7 and SBT3.8 were found to be up-regulated in response to osmotic stress. Stress symptoms were enhanced in sbt3.8 loss-of-function mutants and could be alleviated by PSK treatment. Osmotic stress tolerance was improved in plants overexpressing the precursor of PSK1 (proPSK1) or SBT3.8 resulting in higher fresh weight and improved lateral root development in the transgenic compared to wild-type plants. We further showed that SBT3.8 is involved in the biogenesis of the bioactive PSK peptide. ProPSK1 was cleaved by SBT3.8 at the C-terminus of the PSK pentapeptide. Processing by SBT3.8 depended on the aspartic acid residue directly following the cleavage site. ProPSK1 processing was impaired in the sbt3.8 mutant. The data suggest that increased expression in response to osmotic stress followed by the post-translational processing of proPSK1 by SBT3.8 leads to the production of PSK as a peptide signal for stress mitigation.


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