Project description:Salt stress, especially saline-alkali stress, has seriously negative effect on citrus production. Ziyang xiangcheng (Citrus junos Sieb.) (Cj) has been reported as a saline-alkali stress and iron deficiency tolerant citrus rootstock. However, the molecular mechanism of its saline-alkali stress tolerance is still not clear. Two citrus rootstocks and one navel orange scion, Cj, Poncirus trifoliate (Poncirus trifoliata (L.) Raf.) (Pt) and ‘Lane Late’ navel orange (Citrus sinensis (L.) Osb.) (LL), were used in this study. The grafted materials Cj+LL and Pt+LL grown in calcareous soil were used to identify genes and pathways responsive to saline-alkali stress using RNA-seq. The seedlings of Cj and Pt grown in the solutions with different gradient pH value were used to perform a supplement experiment. Comprehensively analyzing the data of RNA-seq, physiology and biochemistry, agronomic traits and mineral elements of Cj+LL, Pt+LL, Cj and Pt, several candidate pathways and genes were identified to be highly regulated under saline-alkali stress. Here, we propose citrate is important for the tolerance to iron deficiency and the jasmonate (JA) biosynthesis and signal transduction pathway may play a crucial role in tolerance to saline-alkali stress in citrus by interacting with other plant hormones, calcium signaling, ROS scavenging system and lignin biosynthesis.
Project description:Soil salination and alkalization are global problems impairing plant survival by disrupting REDOX homeostasis. Whether melatonin regulates REDOX homeostasis at nitrosative level, and thus affects plant saline-alkali tolerance remains unknown. In saline-alkali stress, excess nitric oxide (NO) causes nitrosative damage in tomato roots. This NO can be degraded by S-nitrosoglutathione reductase (GSNOR), or stimulates caffeic acid O-methyltransferase (COMT) transcript for melatonin synthesis. Melatonin further feedback scavenges excess NO to alleviate nitrosative damage at the whole protein level, indicating by proteome S-nitrosylation. We target plasma membrane H+-ATPase 2 (HA2) and highlight that HA2 is S-nitrosylated at Cys206 in saline-alkali stress, reducing HA activity, H+ efflux, and tolerance by impairing its interaction with 14-3-3 protein 1 (TFT1). In agreement with these observations, COMT-mediated melatonin relieves the HA2 S-nitrosylation to recover its function and saline-alkali tolerance. Therefore, we propose NO and melatonin as a pair of REDOX switches to control HA2 S-nitrosylation and saline-alkali tolerance. Under natural saline-alkali conditions, tomato productivity can be improved by grafting with COMT-, GSNOR-, HA2-overexpression rootstocks or by genetic engineering non-nitrosylated HA2C206S mutants. Using melatonin-NO-HA2 module as a case, this study illuminates a novel molecular function of melatonin and relevant genetic engineering strategies in future agriculture.
Project description:To investigate possible genetic basis of alkali tolerance in rice, we generated an introgressed rice line (K83) with significantly enhanced tolerance to alkali stress than its recipient parental cultivar (Jijing88). By using microarray analysis, we examined global gene expression profiles in K83 and Jijing88, found more than 1,200 genes were constitutively differentially expressed in K83 compared with Jijing88, with 572 up- and 654 down-regulated. Upon alkali treatment, a total of 347 genes in K83 were found up- and 156 down-regulated in K83, compared with 591 and 187 respectively in Jijing88. Seven-day-old uniform-sized seedlings grown in hydroponic medium were transferred to fresh hydroponic medium alone or containing 50 mM alkali salts. Shoots were harvested 24 h after transfer and 10 shoots were pooled for microarray analysis.
Project description:Purpose:Salinity is an important environmental factor that affects the physiological activities of fish. The goals of this study are investigating the effect of different saline-alkali stress on grass carp (Ctenopharyngodon idella). Methods: Grass carp individuals, averaging 12 cm in body length, were obtained from Duofu fish farm (Wuhan, China) and cultured at recirculating aquaculture system for 2 weeks before the experiment began. For the challenge, all grass carp were randomly divided into three groups, and then cultured at saline-alkali water with the concentration of 0, 3‰ and 6‰. After 30 days, some grass crap cultured at 3‰ and 6‰ saline-alkali water were injured. At the same time, gill samples of grass carp were collected from 0, 3‰ (grass carp was not injured), 3‰ (grass carp was injured), 6‰ (grass carp was not injured) and 6‰ (grass carp was injured)saline-alkali groups. Total RNA of all samples was isolated using TRIzol® Reagent (Invitrogen) according to the manufacturer's introduction. RNA integrity was assessed using an Agilent 2100 bioanalyzer (Agilent, USA). Samples with RNA integrity numbers (RINs) ≥ 7.5 were subjected to cDNA library construction using TruseqTM RNA sample prep Kit (Illumina). Results:A total of 15 were processed for transcriptome sequencing, generating 94.99Gb Clean Data. At least 5.76Gb clean data were generated for each sample with minimum 91.87% of clean data achieved quality score of Q30. Clean reads of each sample were mapped to specified reference genome. Mapping ratio ranged from 88.59% to 92.84%. The expression of genes was quantified and differentially expressed genes were identified based on their expression.Criteria for differentially expressed genes was set as Fold Change(FC)≥1.5 and Pvalue<0.05. Fold change(FC) refers to the ratio of gene expression in two samples. These DEGs were further processed for functional annotation and enrichment analysis. Conclusions: Our study represents Effects and molecular regulation mechanisms of saline-alkali stress on the healthy grass carp by using RNA-seqtechnology. Our results show that saline-alkali stress will impair the immune system of grass carp.
Project description:To investigate possible genetic basis of alkali tolerance in rice, we generated an introgressed rice line (K83) with significantly enhanced tolerance to alkali stress than its recipient parental cultivar (Jijing88). By using microarray analysis, we examined global gene expression profiles in K83 and Jijing88, found more than 1,200 genes were constitutively differentially expressed in K83 compared with Jijing88, with 572 up- and 654 down-regulated. Upon alkali treatment, a total of 347 genes in K83 were found up- and 156 down-regulated in K83, compared with 591 and 187 respectively in Jijing88.
2014-05-16 | GSE45724 | GEO
Project description:Jujube Fruits under Saline Alkali Stress
Project description:Soil alkalinity greatly affects plant growth and crop productivity. Although RNA-Seq analyses have been conducted to investigate genome-wide gene expression in response to alkaline stress in many plants, the expression of alkali-responsive genes in rice has not previously investigated. In this study, the transcriptomic data were compared between an alkaline-tolerant [WD20342 (WD)] and an alkaline-sensitive [Caidao (CD)] rice cultivar under control and alkaline stress conditions. A total of 962 important alkali-responsive (IAR) genes from highly differentially expressed genes (DEGs) were identified, including 28 alkaline-resistant cultivar-related genes, 771 alkaline-sensitive cultivar-related genes and 163 cultivar-non-specific genes. Gene ontology (GO) analysis suggested the enrichment of IAR genes involved in response to various stimuli or stresses. According to KEGG pathway analysis, the IAR genes were related primarily to plant hormone signal transduction and biosynthesis of secondary metabolites. Additionally, among these 962 IAR genes, 74 were transcription factors and 15 occurred with differential alternative splicing between the different samples after alkaline treatment. Our results provide a valuable resource on alkali-responsive genes and should benefit the improvement of alkaline stress tolerance in rice.
Project description:Sorghum (Sorghum bicolor) is the fifth most important cereal crop in the world. It is an annual C4 crop having a high biomass, used widely, and has a strong resistance to stress. Obviously, there are many benefits of planting sorghum on marginal soils such as saline-alkali land.