Exogenous proline and trehalose promote recovery of rice. Stress and disease tolerance irri rice knowledge bank. An endophyte from saltadapted pokkali rice confers salt. Effects of abiotic stress on plants the university of. Plants were grown in sodium chloridecontaining soil 2 or 4 dsm2 electrical conductivity, which was imposed 4weeks after transplant called seedling ec2 and ec4 or. Pdf improvement of salinity stress tolerance in rice. Using affymetrix rice genomic arrays, salinityinduced transcript profiles were documented recently in shoot tissues of ir29, a saltsensitive indica cultivar, and.
The consequences of all these can ultimately lead to plant death as result of growth arrest and molecular damage mc cure and hanson, 1990. Salinity inflicted osmotic effects, ion toxicity and nutritional imbalance in rice. The development of improved rice varieties with high tolerance of salt stress has been a major and longstanding goal of rice breeding efforts. Seed invigoration techniques to improve germination and early growth of inbred line of maize under salinity and drought stress. Attempts in understanding salt tolerance mechanisms has revealed several key. The nonliving variable must influence the environment beyond its normal range of variation to adversely affect the population performance or individual physiology of the organism in a significant way. Rice oryza sativa is particularly sensitive to salt stress during the reproductive stage. M r amirjanieffect of salinity stress on growth, sugar content, pigments and enzyme activity of rice. Salinity in soil or water is one of the major stresses, can severely limit crop production shannon, 1998. Despite many attempts using different strategies to improve salinity tolerance in rice, the achievements so far are quite modest. Alleles ranged from 3 in rm493 and rm 3412 to 4 in rm 10793. Mohammad rashed hossain a thesis submitted to the university of birmingham for the degree of doctor of philosophy.
Plant adaptation or tolerance to salinity stress involves complex physiological traits, metabolic pathways, and molecular or gene networks. Salinity effects on seedling growth and yield components. However, rice is very sensitive to salinity and is the most salt sensitive cereal crop with a threshold of 3 dsm. Seed germination is a complex trait determined by both quantitative trait loci qtls and environmental factors and also their interactions. Also osmotic stress imposed by sorbitol did not change ph cyt in rice or quince. Another salt responsive zinc finger protein gene zfp179ox leads to increased salt stress tolerance with increased level of free proline and soluble sugars in transgenic rice sun et al. Cytosolic calcium and ph signaling in plants under. Figure 4, b and c, shows plants recovering for 8 d after a 9d exposure to 200 m m nacl.
Saltresistant rice cultivars nona bokra and ir 4630 exposed at the seedling stage during one or two weeks to 0, 20, 30, 40 or 50 mm nacl accumulated less na, cl, zn and proline and more k at root and shoot levels than saltsensitive i kong pao and ir 31785. Here, we show that transcription factor osmads25 positively regulates the root system development and tolerance to salinity and oxidative stress in rice plants. Abiotic stress is the negative impact of nonliving factors on the living organisms in a specific environment. To test the usefulness of microsatellite ssr markers associated with saltol qtl, a collection of 150 diverse rice genotypes were used. Germination and seedling growth of pulse crop vigna spp. Effect of salinity stress on growth, sugar content. Molecular and physiological traits imparting resistancetolerance and susceptibility to a particular biotic and abiotic stress are important from crop production point of view. In this study, we mapped one major qtlqse3 for seed germination and seedling establishment under salinity stress in rice. Rice shaker potassium channel oskat1 confers tolerance to. The ability of plants to cope with salinity stress is an important determinant of crop distribution. On the basis of tolerance ability toward salinity, rice is considered as salt sensitive crop, and growth and yield of rice are. Susceptibility or tolerance of rice plants to high salinity is a coordinated action of. To understand the molecular basis of this qtl, we isolated qse3 by map. Transcriptome analysis in different rice cultivars provides novel insights into desiccation and salinity stress responses.
Screening six varieties of rice oryzasativa for salinity. Despite many attempts using different strategies to improve salinity tolerance in rice. Salinity stress represents a global constraint for rice, the most important staple food worldwide. Perez af, estan mt, santa cruz a, bolarin mc 1993 effects of salinity on nitrate, total nitrogen, soluble protein and free amino acid. Rice was moderately sensitive to salinity, threshold being ec3 dsin beyond which yield starts decreasing. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid ja biosynthesis rice mutants cpm2 and hebiba impaired in the function of allene oxide. Improvement of salinity stress tolerance in rice mdpi. Pruning the rice plant leaves leaving upper 23 leaves before salinization during the booting stage will not significantly affect yield and other component traits. Results show that rice varieties respond to salinity differently. Salinity threat is estimated to reduce global rice production by 50%.
In rice, increased growth of roots in depth was found under drought stress asch et al. Effects of salinity stress on growth, chlorophyll content and ion accumulation in two indica rice oriza sativa l. Salinity is defined as the presence of excessive amounts of soluble salts in the soil usually measured as electrical conductivity, ec. In recent years, crisprcas9 systems have been widely used for targetsite genome editing. The present research was conducted to evaluate five rice varieties for salinity tolerance at seedling stage. The present study was designed to study the effect of salinity on seed germination, seedling growth and acid phosphatase activities in romaine and vista. Susceptibility and tolerance of rice crop to salt threat plos. The salinity sensitivity of a rice variety is not only determined by the salinity level but also by the salinity stress time. Enhancing trehalose biosynthesis improves yield potential. It would also be the next frontier for integrationfree. Salinity is a major abiotic stress limiting yield in many parts of the world. Two rice genotypes differing in their tolerance of salinity were evaluated in a set of greenhouse experiments under o and 6 dsm1 of salinity. Here we present the most recent data on the salinity effect on rice physiology and stress adaptation, including implications on growth regulation and reproductive development. Effects of timing and severity of salinity stress on rice.
Genetic dissection of salt tolerance in rice louisiana. One set was grown as a control nonstress and other as salt stressed. Effects of salt stress on growth, mineral nutrition and. High salinityinduced osmotic stress increases the biosynthesis of aba. Development of varieties with improved salt tolerance in major field crops is an urgent need to maintain crop productivity in different parts of the world. Worldwide rice is grown on some 400 million hectares of salt affected land. Rice transcription factor osmads25 modulates root growth.
Salinity stress is one of the most devastating abiotic stresses that affect growth, development and productivity of major crops. Effect of salinity stress on growth, sugar content, pigments and enzyme activity of rice. Effects of salt stress on plant growth, stomatal response. L x yang, j y huang, h j yang, g dong, g liu, j zhu, y wangseasonal changes in the effects of freeair co2. Abstract salinity is one of the most important abiotic stress affecting the world rice production. Salt stress imposes serious limitation to the plant growth and productivity and is considered a major threat to global food security. The aim of this work was to examine agronomic, compositional, and functional changes in rice oryza sativa l. Background because soil salinity is a major abiotic constraint affecting crop yield, much research has been conducted to develop plants with improved salinity tolerance.
Insights into genomics of salt stress response in rice. Rice cultivation may be a first choice for improvement of salt tolerance. Challenges and opportunities article pdf available october 2016 with 1,564 reads how we measure reads. The cultivation of salinitytolerant cultivars is the most costeffective and environmentally friendly approach for salinity control. Publications a variety of sorghum, sensitive to salinity, growing in sand culture and watered with a nutrient solution containing increasing concentrations of sodium chloride. Salinity stress impacts many aspects of a plants physiology, making it difficult to study in toto. In the current study, we have characterized 98 unique rice landraces collected from coastal regions of india, affected by submergence and salinity, based on sub1 and saltol quantitative trait loci qtl linked microsatellite markers.
Enhanced rice salinity tolerance via crisprcas9targeted. Rootspecific transcript profiling of contrasting rice. Salinity is a major yieldreducing factor in coastal and arid, irrigated rice production systems. It has been reported that overexpression of bifunctional fusion of the tps and tpp genes of e. Rice crop responses to salinity stress in terms of responses to salinity stress, plants can be divided into t wo groupshalophyte or glycophytebased on their level. Salt stress induces physiochemical alterations in rice grain. Salinity is considered to be a major abiotic stress affecting germination, seedling growth, and crop production in arid and semiarid regions yohannes and abraha, 20. Effect of salinity on chlorophyll concentration, leaf area. It was observed that salinity stress caused a significant decrease in shoot lengths, fresh and dry weights of all rice varieties. Tarom azmoon was exposed to 200 mm nacl for 14 days. To investigate the role that mir528 plays in the plant stress response, we examined transgenic and wildtype control plants under salinity stress using fully developed plants fig. Physiological responses to salinity were evaluated for contrasting genotypes, during the reproductive stage.
Research paper increased tolerance to salt stress in opda. Effects of salinity stress on growth and phenolics of rice. The stressinduced metabolic changes in the rice plant have been intensively studied, but. Instead, it is more tractable to dissect the plants response into traits that are. Salinity is a significant constraint to rice productivity in many inland and coastal ricegrowing areas and, furthermore, is contributing to the loss of arable lands in many countries due to salt. Constitutive expression of rice microrna528 alters plant. Acid phosphatase activity is known to contribute to resistance under salt and water stress by maintaining a certain level of inorganic phosphate. The r eduction in leaf area table 1 of all 18 rice genotypes under salinity stress plants has been attributed to suppressed cell division. Transcriptome analysis in different rice cultivars. The value of electrical pd was smaller for rice grown in higher salinity level and longer duration of nacl application on their growing media. The osmotic effects of salinity stress can be observed immediately after salt application and are believed to continue for the duration of exposure, resulting in inhibited cell expansion and cell division, as well as stomatal closure t.
Experiment was conducted in triplicate and in two sets. Figure 2 timeline of regulations and changes in symplastic waterrelated functions of a plant cell after saltinduced osmotic changes. An increased level of expression of a number of stress related genes, including osdreb2a, osp5cs, osprot, and oslea3 was observed in the transgenic rice. The effect of salt stress on the germination of maize zea. For rice, soil salinity beyond ece 4 dsm is considered moderate salinity while more than 8 dsm becomes high. School of biosciences the university of birmingham august, 20. Rice is susceptible to salinity specifically at the early vegetative and later. Among many genes involved in this pathway, a phytoene synthase gene, ospsy3 and 9cisepoxycarotenoid dioxygenases. Salinity caused a significant reduction on root length and shoot length.
Effects of salt stress on rice growth, development characteristics, and. Under salinity stress, changes of chemical contents also differed among phenolic compounds and rice. Challenges and opportunities thi my linh hoang 1, thach ngoc tran 2, thuy kieu tien nguyen 2, brett williams 1, penelope wurm 3, sean bellairs 3 and sagadevan mundree 1, 1 queensland university of technology qut centre for tropical crops and biocommodities, brisbane, qld 4001, australia. Two yield parameters, tiller number per plant and spikelet number per panicle, have proved most sensitive to salinity and are highly significantly correlated to final seed yield in rice cultivar under salt stress zeng and shannon, 2000. Effects of salt stress on different maize genotypes braz. This study was conducted to determine the correlation between of salinity stress on growth and phenolic compounds in rice.
The results demonstrated that, response of root length to salt stress was more severe than shoot length figure 2. Na, ca, mg, cl, and so4 are the major ions involved. Evaluating physiological responses of plants to salinity. Effects of salinity stress on growth, chlorophyll content. Aiwu, a moderately resistant genotype, exhibited an intermediate behaviour. Carbohydrate metabolism, rice, salinity stress, salt tolerant salinity is a major environmental stress affecting plant productivity and constitutes a problem concerning many areas, with an emphasis on regions with hot and dry climates. This work provides additional information on the roles of exogenously applied osmoprotectants in modifying responses of rice during salinity stress as well as during the recovery period. Among these genotypes, four genotypes ic536558, ic536559, ic536604 and ic5366041 collected from kerala and. Salanity stress in common bean phaseolus vulgaris l. Agronomy free fulltext improvement of salinity stress. A soil is termed saline if its osmotic pressure is approximately 0. Nipponbare grains from plants grown under lowtomoderate salinity stress in the greenhouse. Assessment of salinity tolerance in rice using seedling.
Pdf sciencedirect effects of salt stress on rice growth and. Result of phenotypic response of rice genotypes to salinity stress at seedling stage indicated varied genotypic response. New phenotyping technique for salinity tolerance at. Rice responses to salinity stress in general, plants that are more salttolerant tend to grow more slowly at low salinity levels than less salttolerant. Despite many attempts using different strategies to improve salinity. Breeding for salt tolerance is a major goal for rice breeders for which screens are required to select out tolerant lines for breeding. Author summary plant roots are constantly exposed to a variety of abiotic stresses, and high salinity is one of major limiting conditions that impose constraints on plant growth.
Few reports have addressed the effects of these osmoprotectants on modification of physiological responses during salt stress in rice. The next frontierthe use of genome editing for integration free. Moreover, salinity has an adverse effect on seed germination of many. Salinity is among the most damaging abiotic stresses for rice production which limits its growing area. Effect of salinity on germination, seedling growth and. It is a major agronomic problem in arid and semiarid regions of the world. Effect of salinity stress on growth and carbohydrate. Whatever differences appear among the genotypes will be due to the response of genotype for salinity treatment. Salinity is a major abiotic stress limiting growth and productivity of plants in many areas of the world due to increasing use of poor quality of water for irrigation and soil salinization. It affected almost all phases of growth of rice plant and decreased yield adversely. Growth and cellular cation contents of the transgenic rice cells during salinity stress. Chlorophyll, reproductive stage, rice, salt stress.