Growth, microtuber production and physiological metabolism in virus-free and virus-infected potato in vitro plantlets grown under NaCl-induced salt stress

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.

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Crosstalk between grapevine leafroll-associate virus-3 (GLRaV-3) and NaCl-induced salt stress in in vitro cultures of the red grape ‘Cabernet Sauvignon’

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-020-01987-z ◽

2021 ◽

Author(s):

Xinyi Hao ◽

Bolei Jiao ◽

Zhiming Liu ◽

Xiaowei Wang ◽

Jingyi Wang ◽

...

Keyword(s):

Salt Stress ◽

In Vitro Cultures ◽

Cabernet Sauvignon ◽

Associate Virus ◽

Red Grape

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Shoot Multiplication and Callus Induction of Labisia pumila var. alata as Influenced by Different Plant Growth Regulators Treatments and Its Polyphenolic Activities Compared with the Wild Plant

Molecules ◽

10.3390/molecules26113229 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3229

Author(s):

Mat Yunus Najhah ◽

Hawa Z. E. Jaafar ◽

Jaafar Juju Nakasha ◽

Mansor Hakiman

Keyword(s):

Callus Induction ◽

Antioxidant Activities ◽

Shoot Multiplication ◽

Wild Plants ◽

Wild Plant ◽

Total Phenolic ◽

Nodal Segment ◽

Ms Medium ◽

In Vitro Plantlets

This study aims to investigate whether the in vitro-cultured L. pumila var. alata has higher antioxidant activity than its wild plant. An 8-week-old L. pumila var. alata nodal segment and leaf explants were cultured onto Murashige and Skoog (MS) medium supplemented with various cytokinins (zeatin, kinetin, and 6-benzylaminopurine (BAP)) for shoot multiplication and auxins (2,4-dichlorophenoxyacetic acid (2,4-D) and picloram) for callus induction, respectively. The results showed that 2 mg/L zeatin produced the optimal results for shoot and leaf development, and 0.5 mg/L 2,4-D produced the highest callus induction results (60%). After this, 0.5 mg/L 2,4-D was combined with 0.25 mg/L cytokinins and supplemented to the MS medium. The optimal results for callus induction (100%) with yellowish to greenish and compact texture were obtained using 0.5 mg/L 2,4-D combined with 0.25 mg/L zeatin. Leaves obtained from in vitro plantlets and wild plants as well as callus were extracted and analyzed for their antioxidant activities (DPPH and FRAP methods) and polyphenolic properties (total flavonoid and total phenolic content). When compared with leaf extracts of in vitro plantlets and wild plants of L. pumila var. alata, the callus extract displayed significantly higher antioxidant activities and total phenolic and flavonoid content. Hence, callus culture potentially can be adapted for antioxidant and polyphenolic production to satisfy pharmaceutical and nutraceutical needs while conserving wild L. pumila var. alata.

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Evaluation of Indigenous Olive Biocontrol Rhizobacteria as Protectants against Drought and Salt Stress

Microorganisms ◽

10.3390/microorganisms9061209 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1209

Author(s):

Nuria Montes-Osuna ◽

Carmen Gómez-Lama Cabanás ◽

Antonio Valverde-Corredor ◽

Garikoitz Legarda ◽

Pilar Prieto ◽

...

Keyword(s):

Salt Stress ◽

Abiotic Stresses ◽

Biochemical Parameters ◽

Biocontrol Agent ◽

Negative Effects ◽

Experimental Conditions ◽

Acds Gene ◽

Drought And Salt Stress ◽

Physiological And Biochemical

Stress caused by drought and salinity may compromise growth and productivity of olive (Olea europaea L.) tree crops. Several studies have reported the use of beneficial rhizobacteria to alleviate symptoms produced by these stresses, which is attributed in some cases to the activity of 1-aminocyclopropane-1-carboxylic acid deaminase (ACD). A collection of beneficial olive rhizobacteria was in vitro screened for ACD activity. Pseudomonas sp. PICF6 displayed this phenotype and sequencing of its genome confirmed the presence of an acdS gene. In contrast, the well-known root endophyte and biocontrol agent Pseudomonas simiae PICF7 was defective in ACD activity, even though the presence of an ACD-coding gene was earlier predicted in its genome. In this study, an unidentified deaminase was confirmed instead. Greenhouse experiments with olive ‘Picual’ plants inoculated either with PICF6 or PICF7, or co-inoculated with both strains, and subjected to drought or salt stress were carried out. Several physiological and biochemical parameters increased in stressed plants (i.e., stomatal conductance and flavonoids content), regardless of whether or not they were previously bacterized. Results showed that neither PICF6 (ACD positive) nor PICF7 (ACD negative) lessened the negative effects caused by the abiotic stresses tested, at least under our experimental conditions.

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Expression Level of Mature miR172 in Wild Type and StSUT4-Silenced Plants of Solanum tuberosum Is Sucrose-Dependent

International Journal of Molecular Sciences ◽

10.3390/ijms22031455 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1455

Author(s):

Varsha Garg ◽

Aleksandra Hackel ◽

Christina Kühn

Keyword(s):

Solanum Tuberosum ◽

Wild Type ◽

Potato Plants ◽

Mature Leaves ◽

In Vitro Plantlets ◽

Long Time ◽

Short Time ◽

Cut Leaves

In potato plants, the phloem-mobile miR172 is involved in the sugar-dependent transmission of flower and tuber inducing signal transduction pathways and a clear link between solute transport and the induction of flowering and tuberization was demonstrated. The sucrose transporter StSUT4 seems to play an important role in the photoperiod-dependent triggering of both developmental processes, flowering and tuberization, and the phenotype of StSUT4-inhibited potato plants is reminiscent to miR172 overexpressing plants. The first aim of this study was the determination of the level of miR172 in sink and source leaves of StSUT4-silenced as well as StSUT4-overexpressing plants in comparison to Solanum tuberosum ssp. Andigena wild type plants. The second aim was to investigate the effect of sugars on the level of miRNA172 in whole cut leaves, as well as in whole in vitro plantlets that were supplemented with exogenous sugars. Experiments clearly show a sucrose-dependent induction of the level of mature miR172 in short time as well as long time experiments. A sucrose-dependent accumulation of miR172 was also measured in mature leaves of StSUT4-silenced plants where sucrose export is delayed and sucrose accumulates at the end of the light period.

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Alleviation of Salt Stress in Wheat Seedlings via Multifunctional Bacillus aryabhattai PM34: An In-Vitro Study

Sustainability ◽

10.3390/su13148030 ◽

2021 ◽

Vol 13 (14) ◽

pp. 8030

Author(s):

Shehzad Mehmood ◽

Amir Abdullah Khan ◽

Fuchen Shi ◽

Muhammad Tahir ◽

Tariq Sultan ◽

...

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Stress Tolerance ◽

Bacterial Strain ◽

Acc Deaminase ◽

Wheat Growth ◽

Wheat Seedlings ◽

Pgp Traits ◽

Bacillus Aryabhattai

Plant growth-promoting rhizobacteria play a substantial role in plant growth and development under biotic and abiotic stress conditions. However, understanding about the functional role of rhizobacterial strains for wheat growth under salt stress remains largely unknown. Here we investigated the antagonistic bacterial strain Bacillus aryabhattai PM34 inhabiting ACC deaminase and exopolysaccharide producing ability to ameliorate salinity stress in wheat seedlings under in vitro conditions. The strain PM34 was isolated from the potato rhizosphere and screened for different PGP traits comprising nitrogen fixation, potassium, zinc solubilization, indole acetic acid, siderophore, and ammonia production, along with various extracellular enzyme activities. The strain PM34 showed significant tolerance towards both abiotic stresses including salt stress (NaCl 2 M), heavy metal (nickel, 100 ppm, and cadmium, 300 ppm), heat stress (60 °C), and biotic stress through mycelial inhibition of Rhizoctonia solani (43%) and Fusarium solani (41%). The PCR detection of ituC, nifH, and acds genes coding for iturin, nitrogenase, and ACC deaminase enzyme indicated the potential of strain PM34 for plant growth promotion and stress tolerance. In the in vitro experiment, NaCl (2 M) decreased the wheat growth while the inoculation of strain PM34 enhanced the germination% (48%), root length (76%), shoot length (75%), fresh biomass (79%), and dry biomass (87%) over to un-inoculated control under 2M NaCl level. The results of experiments depicted the ability of antagonistic bacterial strain Bacillus aryabhattai PM34 to augment salt stress tolerance when inoculated to wheat plants under saline environment.

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