Silicon mediates the changes in water relations, photosynthetic pigments, enzymatic antioxidants activity and nutrient uptake in maize seedling under salt stress

2016 ◽  
Vol 62 (4) ◽  
pp. 262-269 ◽  
Author(s):  
Abdul Sattar ◽  
Mumtaz Akhtar Cheema ◽  
Hakoomat Ali ◽  
Ahmad Sher ◽  
Muhammad Ijaz ◽  
...  
Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 696
Author(s):  
Reem H. Alzahib ◽  
Hussein M. Migdadi ◽  
Abdullah A. Al Ghamdi ◽  
Mona S. Alwahibi ◽  
Abdullah A. Ibrahim ◽  
...  

Understanding salt tolerance in tomato (Solanum lycopersicum L.) landraces will facilitate their use in genetic improvement. The study assessed the morpho-physiological variability of Hail tomato landraces in response to different salinity levels at seedling stages and recommended a tomato salt-tolerant landrace for future breeding programs. Three tomato landraces, Hail 548, Hail 747, and Hail 1072 were tested under three salinity levels: 75, 150, and 300 mM NaCl. Salinity stress reduced shoots’ fresh and dry weight by 71% and 72%, and roots were 86.5% and 78.6%, respectively. There was 22% reduced chlorophyll content, carotene content by 18.6%, and anthocyanin by 41.1%. Proline content increased for stressed treatments. The 300 mM NaCl treatment recorded the most proline content increases (67.37 mg/g fresh weight), with a percent increase in proline reaching 61.67% in Hail 747. Superoxide dismutase (SOD) activity decreased by 65% in Hail 548, while it relatively increased in Hail 747 and Hail 1072 treated with 300 mM NaCl. Catalase (CAT) activity was enhanced by salt stress in Hail 548 and recorded 7.6%, increasing at 75 and 5.1% at 300 mM NaCl. It revealed a reduction in malondialdehyde (MDA) at the 300 mM NaCl concentration in both Hail 548 and Hail 1072 landraces. Increasing salt concentrations showed a reduction in transpiration rate of 70.55%, 7.13% in stomatal conductance, and 72.34% in photosynthetic rate. K+/Na+ ratios decreased from 56% for 75 mM NaCl to 85% for 300 mM NaCl treatments in all genotypes. The response to salt stress in landraces involved some modifications in morphology, physiology, and metabolism. The landrace Hail 548 may have better protection against salt stress and observed protection against reactive oxygen species (ROS) by increasing enzymatic “antioxidants” activity under salt stress.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Neelma Munir ◽  
Sheza A. Khilji ◽  
Maryam Shabir ◽  
Zahoor A. Sajid

Ocimum sanctum L. (Tulsi) is the most important medicinal plant that has antimicrobial, antioxidants, and anticarcinogenic effects on human health. Plants, when under stress, gather several antioxidants and osmoprotectants. The present work focuses on the abiotic stress response of Tulsi and its mitigation by the application of ascorbic acid. In addition to this, an enhancement of antioxidant and antimicrobial activity was also analyzed using ascorbic acid. During the present work, when plants were grown under NaCl stress and ascorbic acid (AA) was provided with foliar applications, it ascertained encouraging effects on growth; likewise, its effect remains stable under salinity stress. The enzymatic antioxidants activity showed a significant change in response to AA alone or in combination. The highest catalase activity was recorded in plants subjected to 0.5 mM AA in combination with 100 mM NaCl (0.65 units/mL of enzyme). Likewise, a similar trend was recorded for the superoxide dismutase activity of Tulsi plants. The highest activity of SOD was recorded in plants subjected to 0.5 mM AA in combination with 100 mM NaCl (66.1 units/mg of protein). Flavonoid content showed its highest amount (27.41 mg/g) when plants were treated with 0.5 mM AA + 100 mM NaCl while the highest phenolic content (1.88 mg/g) was analyzed in salt treated plants sprayed with 0.5 mM AA. In the case of antimicrobial activity, 0.5 mM AA treated plants gave the highest value for the Staphylococcus aureus as 2.15 cm and in Clostridium species was 2.1 cm in the plants treated with 1 mM AA alone. Hence, the findings of the present study may lead to the conclusion that AA has a significant role in defense mechanisms of plants in response to salt stress. Further, it enhances the antimicrobial and antioxidant potential of Tulsi plants grown under salt stress.


2017 ◽  
Vol 109 (2) ◽  
pp. 291 ◽  
Author(s):  
Zahra Mirfattahi ◽  
Soheil Karimi ◽  
Mahmoud Reza Roozban

Selecting salt tolerant rootstocks is a sustainable approach for developing fruit trees in salinity prone areas. 60-day-old seedlings of <em>Pistacia vera </em>‘Akbari’ and ‘Ghazvini’, and <em>P. vera</em> ‘Ghazvini’ × <em>P. atlantica </em>(G×A) were subjected to 0, 50, 100 and 150 mM NaCl in half strength Hoagland’s nutrient solution. After 45 days, the growth, water relations, and oxidative damage parameters were investigated. Salt stress reduced plant biomass, height, crown diameter and leaf number, but increased specific leaf area (SLA) of the seedlings. Under salt stress, the growth of ‘Akbari’ seedlings was higher than the other genotypes. Accumulation of malondialdehyde (MDA) and proline was observed in the leaves of salt affected seedlings. ‘Ghazvini’ seedlings had the highest MDA concentration and the lowest cell membrane stability in their leaves. Degredation of photosynthetic pigments under salt stress was lower in the leaves of ‘Akbari’ seedlings than that in other genotypes. Increase in leaf succulence was observed in ‘Akbari’ and G×A seedlings in response to salt stress. Relative water content and concentration of anthocyanins in the leaves of pistachio genotypes remained unchanged under salt stress. The results revealed that monitoring leaf abscission, SLA, leaf succulence, MDA concentration, and photosynthetic pigments provide suitable contrast for screening salt tolerance in pistachio. Furthuremore, ‘Akbari’ was found to be the most salt tolerant genotype.


2019 ◽  
Vol 11 (3) ◽  
pp. 800 ◽  
Author(s):  
Aleksandra Koźmińska ◽  
Alina Wiszniewska ◽  
Ewa Hanus-Fajerska ◽  
Monica Boscaiu ◽  
Mohamad Al Hassan ◽  
...  

This study attempted to determine short-term responses to drought and salt stress in different Silene vulgaris genotypes and to identify potential abiotic stress biochemical indicators in this species. Four populations from contrasting habitats were subjected to drought and three levels of salinity under controlled greenhouse conditions. The determination of several growth parameters after the stress treatments allowed for ranking the tolerance to stress of the four analyzed populations on the basis of their relative degree of stress-induced growth inhibition. This was then correlated with changes in the leaf levels of monovalent ions (Na+, Cl−, and K+), photosynthetic pigments (chlorophylls a and b, carotenoids), osmolytes (total soluble sugars, proline), and non-enzymatic antioxidants (total phenolic compounds and flavonoids). Despite the observed differences, all four populations appeared to be relatively tolerant to both stress conditions, which in general did not cause a significant degradation of photosynthetic pigments and did not generate oxidative stress in the plants. Drought and salinity tolerance in S. vulgaris was mostly dependent on the use of Na+ and K+ for osmotic adjustment under stress, a mechanism that appeared to be constitutive, and not stress-induced, since relatively high concentrations of these cations (without reaching toxic levels) were also present in the leaves of control plants. The inhibition of additional transportation of toxic ions to the leaves, in response to increasing external salinity, seemed to be a relevant mechanism of tolerance, specifically to salt stress, whereas accumulation of soluble sugars under drought conditions may have contributed to tolerance to drought.


Silicon ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 223-230 ◽  
Author(s):  
Abdul Sattar ◽  
Mumtaz A. Cheema ◽  
Ahmad Sher ◽  
Muhammad Ijaz ◽  
Allah Wasaya ◽  
...  

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1660
Author(s):  
Orsolya Borsai ◽  
Mohamad Al Hassan ◽  
Cornel Negrușier ◽  
M. Dolores Raigón ◽  
Monica Boscaiu ◽  
...  

Climate change and its detrimental effects on agricultural production, freshwater availability and biodiversity accentuated the need for more stress-tolerant varieties of crops. This requires unraveling the underlying pathways that convey tolerance to abiotic stress in wild relatives of food crops, industrial crops and ornamentals, whose tolerance was not eroded by crop cycles. In this work we try to demonstrate the feasibility of such strategy applying and investigating the effects of saline stress in different species and cultivars of Portulaca. We attempted to unravel the main mechanisms of stress tolerance in this genus and to identify genotypes with higher tolerance, a procedure that could be used as an early detection method for other ornamental and minor crops. To investigate these mechanisms, six-week-old seedlings were subjected to saline stress for 5 weeks with increasing salt concentrations (up to 400 mM NaCl). Several growth parameters and biochemical stress markers were determined in treated and control plants, such as photosynthetic pigments, monovalent ions (Na+, K+ and Cl−), different osmolytes (proline and soluble sugars), oxidative stress markers (malondialdehyde—a by-product of membrane lipid peroxidation—MDA) and non-enzymatic antioxidants (total phenolic compounds and total flavonoids). The applied salt stress inhibited plant growth, degraded photosynthetic pigments, increased concentrations of specific osmolytes in both leaves and roots, but did not induce significant oxidative stress, as demonstrated by only small fluctuations in MDA levels. All Portulaca genotypes analyzed were found to be Na+ and Cl− includers, accumulating high amounts of these ions under saline stress conditions, but P. grandiflora proved to be more salt tolerant, showing only a small reduction under growth stress, an increased flower production and the lowest reduction in K+/Na+ rate in its leaves.


2011 ◽  
Vol 4 (3) ◽  
pp. 497
Author(s):  
Rayana Pires Marques ◽  
Clarissa Soares Freire ◽  
Hugo Henrique Costa do Nascimento ◽  
Rejane Jurema Mansur Custósio Nogueira

Esta pesquisa objetivou avaliar os efeitos da salinidade nas relacoes hidricas e teor de pigmentos fotossintetizantes em mudas de pitangueira. Para tanto, foi desenvolvido um experimento em casa de vegetacao do Laboratorio de Fisiologia Vegetal, pertencente ao Departamento de Biologia da UFRPE, no periodo de dezembro de 2010 a abril de 2011. O delineamento experimental utilizado foi o inteiramente casualizado com quatro tratamentos salinos: 0 (controle), 30, 60 e 90 mM de NaCl, e com cinco repeticoes por tratamento. Aos 35 e 95 DAD (dias apos diferenciacao) decorreram as analises fisiologicas. Foram mensurados o potencial hidrico foliar e o teor relativo de agua em dois horarios: antemanha (4h) e meiodia (12h) e os pigmentos fotossintetizantes. A alta demanda evaporativa (12 horas) ocasionou reducoes significativas para o potencial hidrico foliar e teor relativo de agua na pitangueira. Nestes horarios tambem ocorreram diferencas nos pigmentos, entre os niveis de salinidade estudados. Os resultados indicam que a imposicao da salinidade propiciou reducoes no status hidrico das plantas. Em relacao aos pigmentos fotossinteticos, o estresse em curto prazo gerou sua diminuicao, porem em longo prazo, gerou aumento dos mesmos. A variavel fotossintetica estudada mais afetada foram os carotenoides. Palavras-chave: Potencial Hidrico Foliar, Teor Relativo de Agua, estresse salino, pigmentos fotossinteticos  Water Relations and Production of Pigments in Seedlings Photosynthetic Eugenia Uniflora l. Under Salinity Conditions   ABSTRACT This research had as objective evaluate the effects of salinity in the hydric relations and photosynthetic pigments amount in Eugenia uniflora L.. A experiment was developed in the greenhouse of the Laboratory of Vegetal Phisiology, UFRPE, Brazil, between December 2010 and April 2011. The experimental was designed with four treatments: 0 (control), 30, 60 and 90 mM NaCl with five repetitions each treatment. At 35 and 95 days of experiment physiological analysis were performed. It was measured the leaf hydric potential and the relative water content, at two different moments: pre-morning, AND MID DAY and the photosynthetic pigments. The high evaporative demand (mid day) caused significant reductions in the leaf hydric potential and relative water content in the E. uniflora. At the referred times it was also possible to observe differences in the photosynthetic pigments between the levels of stressing. Results indicate that the imposition of high salinity reduced the hydric status of the subjects. Relating to the photosynthetic pigments the short-term salt stress caused a reduction that was overcome in the long-term stressing. The most affected pigment studied were the carotenoids.  Keywords: Leaf hydric potential, relative water content, salt stress, photosynthetic pigments


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue-Ming Zai ◽  
Jun-Jun Fan ◽  
Zhen-Ping Hao ◽  
Xing-Man Liu ◽  
Wang-Xiang Zhang

AbstractBeach plum (Prunus maritima) is an ornamental plant, famous for its strong salt and drought stress tolerance. However, the poor growth rate of transplanted seedlings has seriously restricted its application in salinized soil. This study investigated the effects of inoculation with arbuscular mycorrhizal fungus (AMF), Funneliformis mosseae, and phosphate-solubilizing fungus (PSF), Apophysomyces spartima, on the growth, nutrient (N, P, and K) uptake, and photosynthesis of beach plum under saline (170 mM NaCl) and non-saline (0 mM NaCl) conditions. We aimed to find measures to increase the growth rate of beach plum in saline-alkali land and to understand the reasons for this increase. The results showed that salinization adversely affected colonization by AMF but positively increased PSF populations (increased by 33.9–93.3% over non-NaCl treatment). The dual application of AMF and PSF mitigated the effects of salt stress on all growth parameters and nutrient uptake, significantly for roots (dry weight and P and N contents increased by 91.0%, 68.9%, and 40%, respectively, over non-NaCl treatment). Salinization caused significant reductions in net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), and intercellular CO2 concentration (Ci) value, while inoculation with AMF and PSF inoculations significantly abated such reductions. The maximum efficiency of photosystem II (PSII) (Fv/Fm), the photochemical quenching coefficient (qP), and the nonphotochemical quenching (NPQ) values were affected little by inoculation with AMF, PSF, or both under non-NaCl treatments. However, plants inoculated with AMF and/or PSF had higher Fv/Fm, qP, and ФPSII values (increased by 72.5–188.1%) than the control under NaCl treatment, but not a higher NPQ value. We concluded that inoculation with AMF or PSF increased nutrient uptake and improved the gas-exchange and Chl fluorescence parameters of beach plum under salt stress environment. These effects could be strengthened by the combination of AMF and PSF, especially for nutrient uptake, root growth, and Pn, thereby alleviating the deleterious effects of NaCl stress on beach plum growth.


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