Effects of NaCl salinity on seedling growth, senescence, catalase and protease activities in two wheat genotypes differing in salt tolerance (original) (raw)
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Morphobiochemical analysis of salinity stress response of wheat
Pakistan Journal of Botany, 2006
The experiments were planned to investigate the effect of salt stress on morphobiochemical response of wheat cv. Uqab-2000. Seeds were given different priming treatments like hydro priming, chilling, kinetin, CaCl 2 .2H 2 O and controlled (with no treatment). After priming treatments the seedlings were grown under normal and salt stress (NaCl 125 mM) for 8-days in petridishes at 25 ±1°C in an incubator. Various morphological parameters for seedlings and biochemical parameters (catalase activity and ascorbic acid contents) for roots were determined. The results revealed that generally all treatments except hydropriming increased the morphological growth of the seedlings, particularly chilling, kinetin, and calcium chloride showed a significant difference compared to control. An overall increasing trend in the catalase activity (units/ mg fresh weight) was observed except kinetin treatment in normal and chilling in saline conditions. The profound increase in activity of catalase was observed after chilling and hydro priming in normal and saline, respectively. However, all seed priming treatments decreased the ascorbic acid concentration under salinity, while reverse was true for normal conditions. Application of salt stress have overall substantial negative affect on all the visual growth and biochemical parameters, However seed priming treatments tend to alleviate the adverse effects of salinity.
Biologia Plantarum, 2009
The effects of salicylic acid (SA) and salinity on the activity of apoplastic antioxidant enzymes were studied in the leaves of two wheat (Triticum aestivam L.) cultivars: salt-tolerant (Gerek-79) and salt-sensitive (Bezostaya). The leaves of 10-d-old seedlings grown at nutrient solution with 0 (control), 250 or 500 mM NaCl were sprayed with 0.01 or 0.1 mM SA. Then, the activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) were determined in the fresh leaves obtained from 15-d-old seedlings. The NaCl applications increased CAT and SOD activities in both cultivars, compared to those of untreated control plants. In addition, the NaCl increased POX activity in the salt-tolerant while decreased in the salt-sensitive cultivar. In control plants of the both cultivars, 0.1 mM SA increased CAT activity, while 0.01 mM SA slightly decreased it. SA treatments also stimulated SOD and POX activity in the salt-tolerant cultivar but significantly decreased POX activity and had no effect on SOD activity in the saltsensitive cultivar. Under salinity, the SA treatments significantly inhibited CAT activity, whereas increased POX activity. The increases in POX activity caused by SA were more pronounced in the salt-tolerant than in the salt-sensitive cultivar. SOD activity was increased by 0.01 mM SA in the salt-tolerant while increased by 0.1 mM SA treatment in the salt-sensitive cultivar.
Journal of plant nutrition and …, 2006
Salinity has a two-phase effect on plant growth, an osmotic effect due to salts in the outside solution and ion toxicity in a second phase due to salt build-up in transpiring leaves. To elucidate salt-resistance mechanisms in the first phase of salt stress, we studied the biochemical reaction of salt-resistant and salt-sensitive wheat (Triticum aestivum L.) genotypes at protein level after 10 d exposure to 125 mM-NaCl salinity (first phase of salt stress) and the variation of salt resistance among the genotypes after 30 d exposure to 125 mM-NaCl salinity (second phase of salt stress) in solution culture experiments in a growth chamber. The three genotypes differed significantly in absolute and relative shoot and root dry weights after 30 d exposure to NaCl salinity. SARC-1 produced the maximum and 7-Cerros the minimum shoot dry weights under salinity relative to control. A highly significant negative correlation (r 2 = -0.99) was observed between salt resistance (% shoot dry weight under salinity relative to control) and shoot Na + concentration of the wheat genotypes studied. However, the salt-resistant and salt-sensitive genotypes showed a similar biochemical reaction at the level of proteins after 10 d exposure to 125 mM NaCl. In both genotypes, the expression of more than 50% proteins was changed, but the difference between the genotypes in various categories of protein change (up-regulated, down-regulated, disappeared, and new-appeared) was only 1%-8%. It is concluded that the initial biochemical reaction to salinity at protein level in wheat is an unspecific response and not a specific adaptation to salinity.
Physiological and Molecular Changes in Barley and Wheat Under Salinity.pdf
In this study, it was aimed to compare salinity-induced changes in barley (Hordeum vulgare L. cv. Bornova-92) and bread wheat (Triticum aestivum L. cv. Gerek-79). Seeds were germinated under saline conditions (0, 50, 100, 250, and 500 mM NaCl) for 2 days and recovered under non-saline conditions for 2 days. At the end of the salt treatment, germination, water content (WC), total soluble protein content, and catalase (CAT, EC 1.11.1.6) activity were affected in both species, while superoxide dismutase (SOD, EC 1.15.1.1) activity was affected in barley. Salinity affected WC, protein content, and CAT activity in both species, while it affected germination in barley and affected fresh weight and SOD activity in wheat after recovery. Physiological responses of both species were correlated. Expression of αtubulin, Atls1, and Lls1 genes was down-regulated in barley after 250 mM NaCl treatment. HVA1 gene was highly (more than 50-fold) stimulated by salinity in barley. However, αtubulin and Atls1 genes were down-regulated, and Lls1 gene was up-regulated in wheat after recovery from 250-mM NaCl treatment. Increase in HVA1 expression was not significant in wheat. The expression profiles of barley and wheat under salinity are different, and barley tended to regulate gene expression faster than wheat.
Physiological enhancements for alleviation of salt stress in wheat
Pak. J. Bot, 2006
Increased salinity is a severe problem to crop production while pre-sowing seed treatments can effectively induce salt tolerance in plants. The effect of different pre-sowing seed treatments (hydropriming, halopriming (50 mM CaCl 2 .2H 2 O), ascorbate priming (50 mg L -1 ) and pre-sowing chilling treatment (-19 o C) on seed germination, vigor, antioxidants and total soluble protein content was investigated in two wheat (Triticum aestivum L.) cultivars Auqab-2000 (salt tolerant) and MH-97 (salt sensitive) under saline (15 dS m -1 ) or non-saline (4 dS m -1 ) conditions. Of all the seed pretreatments, halopriming followed by hydropriming was the most effective in alleviating the adverse effect of salinity by improving germination and seedling growth of both cultivars. In addition, the effect of ascorbate priming was more pronounced in salt tolerant cultivar as revealed from curtailed mean germination time, improved seedling vigor and enhanced ascorbate contents and catalase (CAT) activity. Salinity significantly increased leaf protein content in both cultivars but the magnitude of increase in protein content was higher in Auqab-2000 as compared to that in MH-97. All pre-sowing seed treatments significantly enhanced superoxide dismutase (SOD) activity in MH-97 while priming with CaCl 2 .2H 2 O and ascorbate were very effective in Auqab-2000 during stress conditions. The salt-tolerant cultivar Auqab-2000 had a better protection against reactive oxygen species (ROS) as shown by increased SOD amd CAT activities under salt stress. In conclusion, halopriming and hydropriming successfully improved the seed performance in both cultivars whereas priming with ascorbate was only effective in salt tolerant cultivar under saline conditions. This benefit was attributed to early and synchronized germination, vigorous stand establishment, and decreased oxidative damage due to enhanced antioxidant system.
International Journal of Scientific and Engineering Research
Proline, glycine-betaine (GB) total phenolics, Na+ and K+ contents their ratio and some oxidative stress indices were studied in leaves of bread wheat cultivars namely Sehar-06, Lu-26, (salt-tolerant) and Miraj-08 and Wafaq-01 (salt-sensitive), grown under salinity treatments carried out in five levels (1< dS/m as control, 2, 4, 8, 16 dS/ m) via sodium chloride in order to find out the resistant cultivars of wheat against salt stress. Under high salt potency significant increase for activities of antioxidant enzymes such as ascorbate peroxidase (APX) and guiacol peroxidase (GPX), in salt tolerant varieties. On the other hand, in salt tolerant varieties, activity of (SOD) and (CAT) were not infected. Meanwhile, under salinity condition the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and (GPX) in sensitive cultivar was lower than control and no significant difference were recorded regarding (APX) activity. Salt tolerant varieties had more am...
Screening for Salt Tolerance in Common and Relatives Wheat via Multiple Parameters
Salt stress represents one of the major limiting factors of plant productivity, especially in arid and semiarid regions. The production of wheat, which is the most important crop in the Middle East, is greatly decreased by salinity. Biologists invest so much time to understand the adaptive mechanism underlies such stress and to increase plant tolerance to it. However, the physiological and biochemical processes of plant under salt stress are not completely known. The present manuscript tries to discriminate between adaptive and damage events in two wild and common wheat cultivars. Peroxidase activity, proline, chlorophyll contents and K + / Na + ratio used as a tool to detecting any variations on two wild Egyptian wheat species (salt-tolerant) i.e. Aegilops ventricosa Tausch. and Aegilops kotschyi Boiss. and two common wheat cultivars (Triticum aestivum L.) i.e. Gemmieza 9 (salt-sensitive) and Sids -1 (salt-tolerant) at germination stage on salt solution with different concentration (0.00, 100 and 200 Mm). Peroxidase activity and proline content increased, significantly, in wild wheat (Aegilops spp.) following by the Sids-1, while Gemmieza 9 was affected drastically than the other cultivars.
h i g h l i g h t s Salt-toxicity on growth and production of ten local wheat cultivars were investigated. PCA and cluster analyses enabled us to identify differential salt-tolerant genotypes. Na þ /K þ ratio and proline content positively correlated with growth of tolerant cultivars. BARI Gom 28 (tolerant) exhibited lower oxidative damage than Gourab (sensitive). a b s t r a c t High salinity is a major constraint for wheat productivity in many countries, including Bangladesh. Here, we examined the effects of salt-induced toxicity on growth and production of 10 local wheat cultivars by analyzing physiological, biochemical and agronomical responses to identify the salt-tolerant attributes among the contrasting genotypes. Results of cluster analyses based on salt tolerance indices of plant growth-related and yield-contributing parameters, ionic balance (Na þ , K þ and Na þ /K þ ratio), and stress indicators (SPAD values and proline) revealed Gourab and Shatabdi as salt-sensitive, BARI Gom 27 and 28 as salt-tolerant and the other six examined varieties as moderately salt-tolerant cultivars. Hierarchical clustering and principle component analyses also demonstrated BARI Gom 27 and 28 as the highest salt-tolerant cultivars, especially in terms of Na þ /K þ ratio and proline level. Additionally, lower accumulations of hydrogen peroxide and malondialdehyde, and higher activities of antioxidant enzymes catalase, peroxidase and ascorbate peroxidase in the salt-tolerant BARI Gom 28 than in the salt-sensitive Gourab indicated reduced oxidative damage in BARI Gom 28 relative to that in Gourab. Collectively, our findings suggest that the optimum growth and yield of salt-tolerant cultivars are associated with decreased Na þ / K þ ratio, increased proline level and reduced oxidative stress. Furthermore, BARI Gom 27 and 28 could be suggested as suitable cultivars for cultivation in salt-affected areas, and the contrasting salt-responsive genotypes can be used as valuable genetic resources in breeding and dissection of molecular mechanisms underlying wheat adaptation to high salinity.
Physiological and Molecular Changes in Barley and Wheat Under Salinity
Applied Biochemistry and Biotechnology, 2015
Soil salinity is abiotic stress which adversely influences on growth, overall development and productivity of plants. The plant response to salinity consists of numerous morphological and cellular changes which function in a well coordinated way to alleviate toxicity and changes therefore. Adaptation of some species to elevated salt concentrations provides evidence for inherent potential existed in plants to survive under unfavorable conditions. It is well identified that tolerance and yield constancy are multifaceted genetic characters and are difficult to establish in crops since salt stress may occur as a disastrous. Salt stress may occur immediately, slowly or continually which may again differ in dose as periodically or gradually become severe during any stage of the life cycle of the plants. Therefore research strategies have to be developed to make the plants adaptable to saline environment to face diverse conditions at any stage of growth. Plant growth and internal changes responds to salinity by a way of rapid osmotic phase which inhibits growth of leaves by hampering photosynthesis and another slower but distraous ionic phase that accelerates senescence of leaves. Plants may adapt to salinity with three different types as osmotic stress tolerance, Na + or Clexclusion and by the way of tissue tolerance to sodium and chloride ions. Nowadays, plant physiology, cell biology and molecular genetics research are providing new insights into the plant response to salinity and to improve tolerance of plants relevant to food production and environmental sustainability. Further improvement in tolerance to salinity may be definitive to find out the genetic resources more easily with the understanding of physiological mechanisms concerned in controlling the responses to stress and also if the plants indicate salt tolerance at morphological or cellular level, selection becomes a suitable applied method. This will definitely give a hand in choosing the wonder plant species for the breeders and to overcome a challenging problem of salinity. Better management of soil resource with wise practices with the tolerant and adaptive varieties could be used successfully for raising crop productivity especially in the areas where salinity is consistent and with huge economic loss to the farmers. Therefore, an understanding of appropriate physiological mechanisms controlling stress tolerance so as to provide plant breeders with appropriate selection criteria is essential. The present review elucidates the biochemical changes and associated reasons of the parameters mainly growth, photosynthesis, polyphenols, nitrogen metanbolis, antioxidant enzymes, carbohydrates and minerals.
Journal of Plant Research, 2020
Salicylic acid (SA) has an important role in drought-tolerance in wheat (Triticum aestivum L.) but its relevance to the salinitytolerance is not well understood. In the present study, possible roles of SA and salinity responses were examined using two wheat cultivars i.e., drought-tolerant Sakha-69 and drought-sensitive Gemaza-1, exposed to 150 mM NaCl. Parameters were determined for growth i.e. fresh or dry mass (FM, DM), osmotic concentration (OC) of organic/inorganic solute, leaf relative water content (LRWC), photosynthesis pigment content (PPC), and selective antioxidant system (AOS) enzyme/ molecule that might be involved in the stress remediation. Sakha-69 exhibited salinity tolerance greater than Gemaza-1 and SA ameliorated their salinity stresses like drought stress, suggesting that a common tolerant mechanism might be involved in the stresses. Salinity decreased root growth by 44-52% more strongly than shoot (36-41%) in FM or those in DM (32-35%). SA ameliorated root growth (40-60%) more efficiently than shoot (6-24%) for DM/FM. These results suggested that salinity and SA might target sensitive roots and hence influencing shoot functions. In fact, salinity reduced PPC by 10-18%, LRWC by 16-28%, and more sensitively, OC of inorganic solutes (K + , Ca 2+ , Mg 2+) in shoot (19-36%) and root (25-59%), except a conspicuous increase in Na + , and SA recovered all the reductions near to control levels. SA and salinity increased additively most parameters for OC of organic solutes (sugars and organic acids) and AOS (glutathione and related enzyme activities), like drought responses. However, SA decreased the Na + and proline contents and catalase activity in a counteracting manner to salinity. It is concluded from this experiment that SA-mediated tolerance might involve two mechanisms, one specific for minerals in root and the other related to drought/dehydration tolerance governed in the whole module systems.