In silico comparative analysis of conserved genes expressed in solanaceous plants under abiotic stresses

The gene expression data was studied in order to analyze genes involved in different abiotic stresses in solanaceous plants. Salt, temperature (heat & cold) and drought are the main abiotic stresses to the plants. Abiotic stress responses are important for sessile organisms like plants because they have to cope with environmental changes to survive. The idea was to analyze those differentially expressed genes, which show common expression in response to different abiotic stress conditions in each plant. Mitogen activated protein kinases (MAPK) are important mediators in signal transmission, connecting the perception of external stimuli to cellular responses. In plants, MAPKs plays a major role in the signaling of abiotic stresses. The expression data were retrieved from gene expression omnibus (GEO) database at NCBI. The set of genes were selected showing up or down regulation in at least two abiotic stresses. These genes were used for searching their involvement in different steps of MAP kinase pathway. Our findings suggest that a common set of genes are the key players in signaling pathway responsible for initiation of cascade of reaction in response to stress. The study will help to understand how the conserved genes are expressing differentially in response to various abiotic stresses. The common genes affecting the MAP kinase pathway might be highly conserved. These genes may be used to study the response of different abiotic stresses in other plant species

Meta-Analysis of Common and Differential Transcriptomic Responses to Biotic and Abiotic Stresses in Arabidopsis thaliana

Environmental stresses adversely affect crop growth and yield, resulting in major losses to plants. These stresses occur simultaneously in nature, and we therefore conducted a meta-analysis in this study to identify differential and shared genes, pathways, and transcriptomic mechanisms involved in Arabidopsis response to biotic and abiotic stresses. The results showed a total of 436/21 significant up-/downregulated differentially expressed genes (DEGs) in response to biotic stresses, while 476 and 71 significant DEGs were respectively up- and downregulated in response to abiotic stresses in Arabidopsis thaliana. In addition, 21 DEGs (2.09%) were commonly regulated in response to biotic and abiotic stresses. Except for WRKY45 and ATXTH22, which were respectively up-/down- and down-/upregulated in response to biotic and abiotic stresses, other common DEGs were upregulated in response to all biotic and abiotic treatments. Moreover, the transcription factors (TFs) bHLH, MYB, and WRKY were the common TFs in response to biotic and abiotic stresses. In addition, ath-miR414 and ath-miR5658 were identified to be commonly expressed in response to both biotic and abiotic stresses. The identified common genes and pathways during biotic and abiotic stresses may provide potential candidate targets for the development of stress resistance breeding programs and for the genetic manipulation of crop plants

Meta-Analysis of Common and Differential Transcriptomic Responses to Biotic and Abiotic Stresses in Arabidopsis thaliana

Environmental stresses adversely affect crop growth and yield, resulting in major losses to plants. These stresses occur simultaneously in nature, and we therefore conducted a meta-analysis in this study to identify differential and shared genes, pathways, and transcriptomic mechanisms involved in Arabidopsis response to biotic and abiotic stresses. The results showed a total of 436/21 significant up-/downregulated differentially expressed genes (DEGs) in response to biotic stresses, while 476 and 71 significant DEGs were respectively up- and downregulated in response to abiotic stresses in Arabidopsis thaliana. In addition, 21 DEGs (2.09%) were commonly regulated in response to biotic and abiotic stresses. Except for WRKY45 and ATXTH22, which were respectively up-/down- and down-/upregulated in response to biotic and abiotic stresses, other common DEGs were upregulated in response to all biotic and abiotic treatments. Moreover, the transcription factors (TFs) bHLH, MYB, and WRKY were the common TFs in response to biotic and abiotic stresses. In addition, ath-miR414 and ath-miR5658 were identified to be commonly expressed in response to both biotic and abiotic stresses. The identified common genes and pathways during biotic and abiotic stresses may provide potential candidate targets for the development of stress resistance breeding programs and for the genetic manipulation of crop plants

Exploring plant tolerance to biotic and abiotic stresses

Plants are exposed to many stress factors, such as drought, high salinity or pathogens, which reduce the yield of the cultivated plants or affect the quality of the harvested products. Arabidopsis thaliana was used as a model plant to study the responses of plants to different sources of stress. With Agrobacterium T-DNA mediated promoter tagging, a novel di-/tripeptide transporter gene AtPTR3 was identified as a wound-induced gene. This gene was found to be induced by mechanical wounding, high salt concentrations, bacterial infection and senescence, and also in response to several plant hormones and signalling compounds, such as salicylic acid, jasmonic acid, ethylene and abscisic acid. Atptr3 mutants of two Arabidopsis ecotypes, C24 and Col-0, were impaired in germination on media containing a high salt concentration, which indicates that AtPTR3 is involved in seed germination under salt stress. Wounding caused local expression of the AtPTR3 gene, whereas inoculation with the plant pathogenic bacterium Erwinia carotovora subsp. carotovora caused both local and systemic expression of the gene. Atptr3 mutants showed increased susceptibility to infection caused by bacterial phytopathogens, E carotovora and Pseudomonas syringae pv. tomato, and the P. syringae type III secretion system was shown to be involved in suppression of the AtPTR3 expression in inoculated plants. Moreover, the Atptr3 mutation was found to reduce the expression of the marker gene for systemic acquired resistance, PR1 and the mutants accumulated reactive oxygen species (ROS) following the treatment of the plants with ROS generating substances. Overall results and observations suggest that the AtPTR3 is a novel and versatile stress responsive gene needed for defence reactions against many stresses. In a second part of the study, the yeast (Saccharomyces cerevisiae) trehalose-6-phosphate synthase gene (ScTPS1) was utilized to improve the drought tolerance of Arabidopsis. This gene codes for the first enzyme in the trehalose biosynthesis pathway of yeast, and expression in plants leads to improved drought tolerance but also growth aberrations. In this study, the ScTps1 protein was expressed in Arabidopsis using the constructs containing chloroplast targeting transit peptide sequence that facilitated the import of the ScTps1 into the chloroplast. The drought tolerance and growth phenotypes of Arabidopsis transgenics transformed with ScTPS1 with or without transit peptide, were characterized. The plants with cytosolic localization of the ScTps1 protein showed aberrant root phenotype, but the plants with the chloroplast targeted ScTps1 protein caused no aberration in root morphology. Even though both the transgenic lines showed enhanced drought tolerance, the relative water content of the lines was found to be similar to the wild type control. Moreover, both the transgenic lines showed slightly better water holding capacity or reduced water loss over time compared to wild type plants. The overall results indicated that the growth aberrations caused by cytosolic localization of ScTps1 could be uncoupled from the enhanced drought tolerance in the transgenic plants when the ScTps1 was targeted to chloroplast

Understanding the impacts of crude oil and its induced abiotic stresses on agrifood production: a review

In many parts of the world, the agricultural sector is faced with a number of challenges including those arising from abiotic environmental stresses which are the key factors responsible for most reductions in agrifood production. Crude oil contamination, an abiotic stress factor and a common environmental contaminant, at toxic levels has negative impacts on plants. Although various attempts have been made to demonstrate the impact of abiotic stresses on crops, the underlying factors responsible for the effects of crude oil and its induced abiotic stresses on the composition of the stressed plants are poorly understood. Hence, this review provides an in-depth examination of the: (1) effect of petroleum hydrocarbons on plants; (2) impact of abiotic environmental stresses on crop quality; (3) mechanistic link between crude oil stress and its induced abiotic stresses; as well as (4) mode of action/plant response mechanism to these induced stresses. The paper clearly reveals the implications of crude oil-induced abiotic stresses arising from the soil-root-plant route and from direct application on plant leaves

Potential of plant's Bowman-Birk protease inhibitor in combating abiotic stresses: a mini review

Bowman-Birk Inhibitor (BBI) is one of the subfamilies of serine protease inhibitors. Numerous studies have shown that in plants, BBI functions as part of their defense mechanism against pathogens and microorganisms. The BBI is also known to have anti-carcinogenic properties. Furthermore, the BBI has been reported to function in controlling abiotic stresses such as salinity and drought stresses. Abiotic stresses are the major problems in agricultural industry. Therefore, numerous researches have been carried out to characterize the BBI and to determine its roles during biotic and abiotic stresses. This paper presents a review regarding the relationship between Bowman-Birk inhibitor and the plant defensive mechanism against abiotic stresses

Consistent alleviation of abiotic stress with silicon addition: a meta-analysis

1. Hundreds of single species studies have demonstrated the facility of silicon (Si) to alleviate diverse abiotic stresses in plants. Understanding of the mechanisms of Si-mediated stress alleviation is progressing, and several reviews have brought information together. A quantitative assessment of the alleviative capacity of Si, however, which could elucidate plant Si function more broadly, was lacking. 2. We combined the results of 145 experiments, predominantly on agricultural species, in a meta-analysis to statistically assess the responses of stressed plants to Si supply across multiple plant families and abiotic stresses. We interrogated our database to determine whether stressed plants increased in dry mass and net assimilation rate, oxidative stress markers were reduced, antioxidant responses were increased and whether element uptake showed consistent changes when supplied with Si. 3. We demonstrated that across plant families and stress types, Si increases dry weight, assimilation rate and chlorophyll biosynthesis and alleviates oxidative damage in stressed plants. In general, results indicated that plant family (as a proxy for accumulator type) and stress type had significant explanatory power for variation in responses. The consistent reduction in oxidative damage was not mirrored by consistent increases in antioxidant production, indicative of the several different stress alleviation mechanisms in which Si is involved. Silicon addition increased K in shoots, decreased As and Cd in roots and Na and Cd in shoots. Silicon addition did not affect Al, Ca or Mn concentration in shoots and roots of stressed plants. Plants had significantly lower concentrations of Si accumulated in shoots but not in roots when stressed. 4. Meta-analyses showed consistent alleviation by Si of oxidative damage caused by a range of abiotic stresses across diverse species. Our findings indicate that Si is likely to be a useful fertilizer for many crops facing a spectrum of abiotic stresses. Similarities in responses across families provide strong support for a role of Si in the alleviation of abiotic stress in natural systems, where it has barely been explored. We suggest this role may become more important under a changing climate and more experiments using non-agricultural species are now needed

Advances in genetic engineering for plants abiotic stress control

Agricultural productivity is highly influenced by abiotic stresses, known as the most harmful factor concerning the growth and productivity of crops worldwide. Furthermore, industrial crops are nowadays highly influenced by abiotic stress; these include extremes in temperature, drought, salinity, heavy metals and radiation. Typical studies were discussed by many researchers about the control of abiotic stress in plants by the expression, over-expression or switching off abiotic stress-related genes. Despite the rapid evolution of the research, some crops are still expected to decline by 15 to 32% in the next fifty years. Consequently, engineering genes that protect and maintain the function and structure of cellular components can enhance tolerance to stress. This review presents principal methods adapted in the control of plants abiotic stresses including recent advances in using transgenes for the improvement of abiotic stress tolerance in plants. Specified analysis of recent advances in abiotic stress control could describe trehalose as a better compound in the control of plant abiotic stresses. Therefore, studies of genes-related trehalose metabolism and associated patterns could not only provide an improved plant metabolism, phenotypes and texture, but in fact, the plants become highly resistant to abiotic stress.Key words: Abiotic stresses, crops, expression, over-expression, switching off, trehalose, genes-related