scholarly journals Transcriptome profiling reveals the effects of drought tolerance in Giant Juncao

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Zhou ◽  
Siqi Chen ◽  
Wenjiao Shi ◽  
Rakefet David-Schwartz ◽  
Sutao Li ◽  
...  

Abstract Background Giant Juncao is often used as feed for livestock because of its huge biomass. However, drought stress reduces forage production by affecting the normal growth and development of plants. Therefore, investigating the molecular mechanisms of drought tolerance will provide important information for the improvement of drought tolerance in this grass. Results A total of 144.96 Gb of clean data was generated and assembled into 144,806 transcripts and 93,907 unigenes. After 7 and 14 days of drought stress, a total of 16,726 and 46,492 differentially expressed genes (DEGs) were observed, respectively. Compared with normal irrigation, 16,247, 23,503, and 11,598 DEGs were observed in 1, 5, and 9 days following rehydration, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed abiotic stress-responsive genes and pathways related to catalytic activity, methyltransferase activity, transferase activity, and superoxide metabolic process. We also identified transcription factors belonging to several families, including basic helix-loop-helix (bHLH), WRKY, NAM (no apical meristem), ATAF1/2 and CUC2 (cup-shaped cotyledon) (NAC), fatty acyl-CoA reductase (FAR1), B3, myeloblastosis (MYB)-related, and basic leucine zipper (bZIP) families, which are important drought-rehydration-responsive proteins. Weighted gene co-expression network analysis was also used to analyze the RNA-seq data to predict the interrelationship between genes. Twenty modules were obtained, and four of these modules may be involved in photosynthesis and plant hormone signal transduction that respond to drought and rehydration conditions. Conclusions Our research is the first to provide a more comprehensive understanding of DEGs involved in drought stress at the transcriptome level in Giant Juncao with different drought and recovery conditions. These results may reveal insights into the molecular mechanisms of drought tolerance in Giant Juncao and provide diverse genetic resources involved in drought tolerance research.

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 640
Author(s):  
Fayas Thayale Purayil ◽  
Balaji Rajashekar ◽  
Shyam S. Kurup ◽  
Abdul Jaleel Cheruth ◽  
Sreeramanan Subramaniam ◽  
...  

Haloxylon persicum is an endangered western Asiatic desert plant species, which survives under extreme environmental conditions. In this study, we focused on transcriptome analysis of H. persicum to understand the molecular mechanisms associated with drought tolerance. Two different periods of polyethylene glycol (PEG)-induced drought stress (48 h and 72 h) were imposed on H. persicum under in vitro conditions, which resulted in 18 million reads, subsequently assembled by de novo method with more than 8000 transcripts in each treatment. The N50 values were 1437, 1467, and 1524 for the control sample, 48 h samples, and 72 h samples, respectively. The gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis resulted in enrichment of mitogen-activated protein kinase (MAPK) and plant hormone signal transduction pathways under PEG-induced drought conditions. The differential gene expression analysis (DGEs) revealed significant changes in the expression pattern between the control and the treated samples. The KEGG analysis resulted in mapping transcripts with 138 different pathways reported in plants. The differential expression of drought-responsive transcription factors depicts the possible signaling cascades involved in drought tolerance. The present study provides greater insight into the fundamental transcriptome reprogramming of desert plants under drought.


2019 ◽  
Vol 39 (12) ◽  
pp. 2027-2044 ◽  
Author(s):  
Xiangyu Li ◽  
Lihua Xie ◽  
Huifang Zheng ◽  
Miaomiao Cai ◽  
Zhanchao Cheng ◽  
...  

Abstract The juvenile shoots of Phyllostachys edulis have been used as a food source for thousands of years, and it is recognized as a potential source of nutraceuticals. However, its rapid senescence restricts bamboo production and consumption, and the underlying molecular mechanisms of rapid shoot senescence remain largely unclear. In the present study, transcriptome profiling was employed to investigate the molecular regulation of postharvest senescence in shoots, along with physiological assays and anatomical dissections. Results revealed a distinct shift in expression postharvest, specifically transitions from cellular division and differentiation to the relocation of nutrients and programmed cell death. A number of regulatory and signaling factors were induced during postharvest senescence. Moreover, transcription factors, including NAM, ATAF and CUC (NAC) transcription factors, basic helix–loop–helix transcription factors, basic region/leucine zipper transcription factors, MYB transcription factors and WRKY transcription factors, were critical for shoot postharvest senescence, of which NACs were the most abundant. PheNAP2 and PheNAP3 were induced in postharvest shoots and found to promote leaf senescence in Arabidopsis by inducing the expression of AtSAG12 and AtSAG113. PheNAP2 and PheNAP3 could both restore the stay-green Arabidopsis nap to the wild-type phenotype either under normal growth condition or under abscisic acid treatment. Collectively, these results suggest that PheNAPs may promote shoot senescence. These findings provide a systematic view of shoot senescence and will inform future studies on the underlying molecular mechanisms responsible for shoot degradation during storage.


2021 ◽  
Author(s):  
Baozhu Li ◽  
Ruonan Fan ◽  
Guiling Sun ◽  
Ting Sun ◽  
Yanting Fan ◽  
...  

Abstract Background and aims As drought threatens the yield and quality of maize (Zea mays L.), it is important to dissect the molecular basis of maize drought tolerance. Flavonoids, participate in the scavenging of oxygen free radicals and alleviate stress-induced oxidative damages. This study aims to dissect the function of flavonoids in the improvement of maize drought tolerance. Methods Using far-infrared imaging screening, we previously isolated a drought overly insensitivity (doi) mutant from an ethyl methanesulfonate (EMS)-mutagenized maize library and designated it as doi57. In this study, we performed a physiological characterization and transcriptome profiling of doi57 in comparison to corresponding wild-type B73 under drought stress. Results Under drought stress, doi57 seedlings displayed lower leaf-surface temperature (LST), faster water loss, and better performance in growth than B73. Transcriptome analysis reveals that key genes involved in flavonoid biosynthesis are enriched among differentially expressed genes in doi57. In line with these results, more flavonols and less hydrogen peroxide (H2O2) were accumulated in guard cells of doi57 than in those of B73 with the decrease of soil water content (SWC). Moreover, the capacity determined from doi57 seedling extracts to scavenge oxygen free radicals was more effective than that of B73 under the drought treatment. Additionally, doi57 seedlings had higher photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency than B73 exposed to drought stress, resulting in high biomass and greater root/shoot ratios in doi57 mutant plants. Conclusion Flavonoids may facilitate maize seedling drought tolerance by lowering drought-induced oxidative damage as well regulating stomatal movement.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2149
Author(s):  
Nkulu Kabange Rolly ◽  
Byung-Wook Yun

Nitrogen (N) is an essential macronutrient, which contributes substantially to the growth and development of plants. In the soil, nitrate (NO3) is the predominant form of N available to the plant and its acquisition by the plant involves several NO3 transporters; however, the mechanism underlying their involvement in the adaptive response under abiotic stress is poorly understood. Initially, we performed an in silico analysis to identify potential binding sites for the basic leucine zipper 62 transcription factor (AtbZIP62 TF) in the promoter of the target genes, and constructed their protein–protein interaction networks. Rather than AtbZIP62, results revealed the presence of cis-regulatory elements specific to two other bZIP TFs, AtbZIP18 and 69. A recent report showed that AtbZIP62 TF negatively regulated AtbZIP18 and AtbZIP69. Therefore, we investigated the transcriptional regulation of AtNPF6.2/NRT1.4 (low-affinity NO3 transporter), AtNPF6.3/NRT1.1 (dual-affinity NO3 transporter), AtNRT2.1 and AtNRT2.2 (high-affinity NO3 transporters), and AtGLU1 and AtGLU2 (both encoding glutamate synthase) in response to drought stress in Col-0. From the perspective of exploring the transcriptional interplay of the target genes with AtbZIP62 TF, we measured their expression by qPCR in the atbzip62 (lacking the AtbZIP62 gene) under the same conditions. Our recent study revealed that AtbZIP62 TF positively regulates the expression of AtPYD1 (Pyrimidine 1, a key gene of the de novo pyrimidine biosynthesis pathway know to share a common substrate with the N metabolic pathway). For this reason, we included the atpyd1-2 mutant in the study. Our findings revealed that the expression of AtNPF6.2/NRT1.4, AtNPF6.3/NRT1.1 and AtNRT2.2 was similarly regulated in atzbip62 and atpyd1-2 but differentially regulated between the mutant lines and Col-0. Meanwhile, the expression pattern of AtNRT2.1 in atbzip62 was similar to that observed in Col-0 but was suppressed in atpyd1-2. The breakthrough is that AtNRT2.2 had the highest expression level in Col-0, while being suppressed in atbzip62 and atpyd1-2. Furthermore, the transcript accumulation of AtGLU1 and AtGLU2 showed differential regulation patterns between Col-0 and atbzip62, and atpyd1-2. Therefore, results suggest that of all tested NO3 transporters, AtNRT2.2 is thought to play a preponderant role in contributing to NO3 transport events under the regulatory influence of AtbZIP62 TF in response to drought stress.


2020 ◽  
Author(s):  
Guori Gao ◽  
Zhongrui Lv ◽  
Guoyun Zhang ◽  
Jiayi Li ◽  
Jianguo Zhang ◽  
...  

Abstract Drought is the most severe abiotic stress and hinders the normal growth and development of plants. Sea buckthorn (Hippophae rhamnoides Linn.) is a typical drought-resistant tree species. In this study, the leaves of the H. rhamnoides ssp. sinensis (“FN”) and H. rhamnoides ssp. mongolica (“XY”) were selected during drought-recovery cycles for RNA sequencing, and physiological and biochemical analyses. The results revealed that drought stress significantly decreased leaf water potential, net photosynthetic rate, and stomatal conductance in both sea buckthorn subspecies. Similarly, the contents of flavone, flavonol, isoflavone and flavanone significantly decreased under drought stress in “XY.” Conversely, in “FN,” the flavone and abscisic acid (ABA) contents were significantly higher under drought stress and recovered after rehydration. Meanwhile, 4,618 and 6,100 differentially expressed genes (DEGs) were identified under drought stress in “FN” and “XY,” respectively. In total, 5,164 DEGs were observed in the comparison between “FN” and “XY” under drought stress. This was more than the 3,821 and 3,387 DEGs found when comparing the subspecies under control and rehydration conditions, respectively. These DEGs were mainly associated with carotenoid biosynthesis, flavonoid biosynthesis, photosynthesis, and plant hormone signal transduction. Six hub DEGs (ABCG5, ABCG22, ABCG32, ABCG36, ABF2 and PYL4) were identified to respond to drought stress based on WGCNA and BLAST analysis using DroughtDB. These six DEGs were annotated to play roles in the ABA-dependent signaling pathway. Sixteen RNA sequencing results involving eight genes and similar expression patterns (12/16) were validated using quantitative real-time PCR. The biochemical and molecular mechanisms underlying the regulation of drought responses by ABA and flavonoids in sea buckthorn were clarified. In this study, gene co-expression networks were constructed, and the results suggested that the mutual regulation of ABA and flavonoid signaling contributed to the difference in drought resistance between the different sea buckthorn subspecies.


2020 ◽  
Vol 32 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Qiaoying Chang ◽  
Xin Lu ◽  
Zhi Liu ◽  
Zhimin Zheng ◽  
Song Yu

AbstractThe basic leucine zipper (bZIP) transcription factor family is one of the largest and most diverse families in plants, regulating plant growth and development and playing an essential role in response to abiotic and biotic stresses. However, little is known about the biological functions of bZIP proteins in yellowhorn (Xanthoceras sorbifolium). Recently, 64 XsbZIP genes were identified in the yellowhorn genome and found to be disproportionately distributed in linkage groups. The XsbZIP proteins clustered into 11 groups based on their phylogenetic relationships with AtbZIP, ZmbZIP and GmbZIP proteins. Five intron patterns in the basic and hinge regions and additional conserved motifs were defined, both supporting the group classification and possibly contributing to their functional diversity. Compared to tandem duplication, the segment duplication greatly contributed to the expansion of yellowhorn bZIP genes. In addition, most XsbZIP genes harbor several stress responsive cis-elements in their promoter regions. Moreover, the RNA-seq and qRT-PCR data indicated XsbZIP genes were extensively involved in response to various stresses, including salt (NaCl), cold and abscisic acid, with possibly different molecular mechanisms. These results provide a new understanding of the biological functions of bZIP transcription factors in yellowhorn.


2020 ◽  
Vol 21 (15) ◽  
pp. 5378 ◽  
Author(s):  
Effi Haque ◽  
M. Rezaul Karim ◽  
Aamir Salam Teeli ◽  
Magdalena Śmiech ◽  
Paweł Leszczynski ◽  
...  

NF-E2-related factor 2 (NRF2) is a basic leucine zipper transcription factor, a master regulator of redox homeostasis regulating a variety of genes for antioxidant and detoxification enzymes. NRF2 was, therefore, initially thought to protect the liver from oxidative stress. Recent studies, however, have revealed that mutations in NRF2 cause aberrant accumulation of NRF2 in the nucleus and exert the upregulation of NRF2 target genes. Moreover, among all molecular changes in hepatocellular carcinoma (HCC), NRF2 activation has been revealed as a more prominent pathway contributing to the progression of precancerous lesions to malignancy. Nevertheless, how its activation leads to poor prognosis in HCC patients remains unclear. In this review, we provide an overview of how aberrant activation of NRF2 triggers HCC development. We also summarize the emerging roles of other NRF family members in liver cancer development.


2018 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ~20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.


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