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