Project description:In many potato cultivation regions, production is constrained by abiotic stresses such as drought and high temperatures which are often present in combination. We aimed to identify key mechanisms and processes underlying single and combined abiotic stress tolerance by a comparative analysis of tolerant and susceptible cultivars. Physiological data supported cultivars Desiree and Unica as being abiotic stress tolerant, while Agria and Russett Burbank were stress susceptible. This was indicated by the stronger impact of abiotic stress on photosynthetic carbon assimilation in the susceptible cultivars. Similarly, susceptible cultivars exhibited a lower leaf transpiration rate following stress, particularly combined heat and drought stress. Transcript profiles using microarrays were highly divergent both between genotypes and following the application of stress treatments. However, relatively few transcripts or metabolites exhibited genotype specific responses to abiotic stress treatment. Furthermore, apart from a decrease in the abundance of transcripts associated with PSII, particularly the light harvesting complex in both Desiree and Unica, there were very few changes that were consistent across stress susceptible or stress tolerant genotypes following stress treatment.
Project description:Nitrogen (N) is an abundant and essential macronutrient for plants growth and development processes, especially for the huge banana trees with high biomass. In this paper, we studied the response of banana resists to low N stress ueing Illumina RNA-Seq technology, and analyzed the DEGs associated with the absorption, transport, and ulitilize of nitrogen.
Project description:'Systems-wide' approaches such as microarray RNA-profiling are ideally suited to the study of the complex, overlapping responses of plants to biotic and abiotic stresses. However, commercial microarrays are only available for a limited number of plant species and development costs are so substantial as to be prohibitive for most research groups. Here, we evaluate the use of cross-hybridisation to Affymetrix oligonucleotide GeneChip microarrays to profile the response of the banana (Musa sp.) leaf transcriptome to drought stress using a genomic DNA (gDNA)-based probe-selection strategy to improve the efficiency of detection of differentially expressed Musa transcripts. GeneChip analyses were performed to profile the response of the banana (Musa sp.) leaf transcriptome to drought stress using a genomic DNA (gDNA)-based probe-selection strategy to improve the efficiency of detection of differentially expressed Musa transcripts.
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under control and drought stressed conditions during vegetative phase. Keywords: Drought response
Project description:A customized targeted oligoarray was used to monitor the expression levels of 1000 genes, representative of the immature kernel transcriptome. Using this oligoarray we compared transcripts from 10 DAP kernels of two susceptible and two drought tolerant genotypes. These four genotypes were extracted from our RIL population (B73xH99) and grown under water stress and well watered field conditions. Keywords: Stress response Two-condition experiment: water stress field condition vs. well watered field condition. Transcriptional profiling of 10 DAP kernel (two susceptible and two drought tolerant genotypes) in the first condition vs 10 DAP kernel (two susceptible and two drought tolerant genotypes) in the second condition. Hybridization replicates: 4 in dye swap mode. Two probes per gene per array.
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under control and drought stressed conditions during vegetative phase. Keywords: Drought response We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during drought stress. We used two contrasting rice genotypes (IR64 drought susceptible and Apo drought tolerant) differing in their degree of drought tolerance. Plants were grown under green house conditions and drought stress was imposed on 33rd DAS. Leaf sampling was done in both control and drought stressed plants after 6 days of drought stress. Three replications of microarray experiments were carried out by hybridizing the control samples against the drought stressed samples.
Project description:Potassium (K+) is a crucial macronutrient in high biomass plants, especially in banana.we comparatively studyed the phenotypic traits and transcriptomic profiles of banana leaves and roots between low potassium group (LK) and normal-potassium group (NK). In our study, the K+ content and biomass index of banana seedling were all significantly decreased under the stress of low potassium group. Moreover, thirty differentially expressed genes (DEGs) related to potassium transport and uptake and transcription factors were analyzed deeply. DEGs about ABC transporters, protein kinases and ion transporters were also detected, these genes may play important roles during potassium deficiency. These results provide valuable information about banana response to low potassium conditions.
Project description:Banana is an important tropical fruit with high value. One main specie (cultivar Cavendish) is susceptible to low temperature, another close relative specie (Dajiao), considerably higher cold tolerance than Cavendish. Our previous global proteomics results suggested that some membrane proteins be likely involved in cold tolerance of Dajiao via antioxidation mechanism. To further investigate early cold stress response of Dajiao, we applied comparative membrane proteomics analysis for both cold-sensitive Cavendish and cold-tolerant Dajiao subjected to 10 °C for 0, 3 and 6 h.
Project description:‘Pulsechip’, a boutique cDNA microarray, generated from a set of chickpea (Cicer arietinum L.) unigenes, grasspea (Lathyrus sativus L.) ESTs and lentil (Lens culinaris Med.) resistance gene analogs, was employed to generate an expression profile of chickpea accessions tolerant and susceptible to drought stress. Two groups of a tolerant and susceptible accession were challenged with drought stress. The experiments were performed in three biological replications. The experiments were conducted in reference design where respective tissues from unstressed plants served as control. The leaf and flower/bud tissues were collected and used for hybridization to measure changes in RNA abundance of treatment vs. control. The tissues from five experimental replicate plants per biological replication were pooled together (leaf and flower tissues separate) before RNA extraction. This RNA was used to prepare cDNA targets for expression analysis using microarray. The microarray had six technical replicate spots per EST. The transcript level for each EST/cDNA was firstly calculated as the average intensity of the six technical replicates and then the average intensity of three biological replicates. Data analysis included LOWESS normalization (LOcally WEighted polynomial regreSSion) to adjust for differences in quantity of initial RNA, labeling and detection efficiencies. A dye swap in one biological replicate adjusted dye bias, if any. The Differentially Expressed (DE) ESTs were identified as those with a 95% confidence interval for mean fold change (FC) that extended beyond the two-fold cut-off and also passed the Students t test (P<0.05) and FDR correction. These cut-offs translate into induced ESTs having a log2 ratio > 1 and repressed ESTs a ratio of < -1. The analysis consisted of three fold comparison. Firstly, the ESTs that were differentially expressed between treatment and control plants of each accession were detected. Then the ESTs that were similarly expressed by tolerant and susceptible accessions were then eliminated by comparison. This included a two-way comparison, where tolerant and susceptible genotypes were compared within and between groups. Lastly, ESTs that were consensually differentially expressed between tolerant and susceptible accessions of the two batches were identified. The hypothesis was that if a putative gene was consistently expressed only in tolerant or susceptible genotype for a particular stress, it might be a candidate for tolerance/susceptibility for that stress. Globally, the level of 114 transcripts was affected in response to drought stress in all the genotypes and tissue types studied. The DE transcripts in response to drought stress coded for various functional and regulatory proteins, most of which were repressed. Protein and other solute transport was repressed in susceptible-1 flowers but induced in tolerant-2 flowers, as evidenced by the induction of a protein-transport facilitation protein (DY475074) in flowers of tolerant-2 and repression of a aquaporin-like membrane channel protein (DY396334) and DNA-J like protein involved in intracellular protein transport (DY475488) in flowers of susceptible-1. Two putative auxin-repressed proteins (DY396289, DY396359) were highly repressed in flowers and leaves of tolerant-2, whilst being induced in flowers and leaves of susceptible-1. Defence-related genes including pathogenesis-related proteins (DY396305 and DY396343), nematode-resistance protein (CV793603), Cf-9 gene cluster (DY396352) and disease resistance response proteins (DY396265 and DY396276) were repressed in flowers of tolerant and susceptible genotypes. A Pea (pi230) disease resistance response protein (DY396390) and a multi-resistance protein ABC transporter (CV793605) were induced in flowers of both tolerant genotypes. Some genes involved in energy metabolism (DY396279 and DY475316) were repressed in leaves and flowers of tolerant and susceptible genotypes. Additionally, some transcripts related to senescence, including auxin responsive protein IAA9 (DY396315), senescence-associated protein DIN 1 (DY396338), and dehydration stress-induced protein (DY396321) were repressed in leaves and flowers of the tolerant genotypes. Of the 114 DE transcripts expressed in drought tolerant and susceptible genotypes, only two were consistently expressed. These included a cytosolic fructose 1,6-bisphosphatase (DY475548) and a gene with unknown function, which were repressed in flowers of both susceptible genotypes. Keywords: Chickpea, Drought stress, Tolerant, Susceptible, cDNA microarray