Jasmonic Acid Differentially Affects Growth, Ion Uptake and Abscisic Acid Concentration in Salt-tolerant and Salt-sensitive Rice Cultivars

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

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Abscisic Acid Content and Osmotic Relations of Salt-Stressed Grapevine Leaves

Functional Plant Biology ◽

10.1071/pp9810443 ◽

1981 ◽

Vol 8 (5) ◽

pp. 443 ◽

Cited By ~ 22

Author(s):

WJS Downton ◽

BR Loveys

Keyword(s):

Abscisic Acid ◽

Acid Concentration ◽

Stomatal Resistance ◽

Vitis Vinifera L ◽

Phaseic Acid ◽

Ion Content ◽

Grapevine Leaves ◽

Abscisic Acid Content ◽

Osmotic Potentials ◽

Reducing Sugar Concentration

Changes in abscisic acid, phaseic acid, stomatal resistance, water potential, osmotic potential, turgor potential, proline, reducing sugars and ion content (Na+, K+, Cl-) in leaves from grapevines (Vitis vinifera L.) subjected to 0, 25, 50 or 100 mM NaCl (osmotic potentials of 0, - 0.1, - 0.2 and - 0.4 MPa, respectively) were monitored over a 3-week period. Abscisic acid concentration increased within 6 h for the 50 and 100 mM NaCl-treated vines. Proline did not accumulate until the next day for the 100 mM NaCl-treated plants and continued to accumulate for the duration of the experiment. Phaseic acid showed kinetics consistent with its being derived from abscisic acid. Stomatal resistance to water vapour exchange increased in the salt-treated plants over the course of the experiment despite a decline in abscisic acid concentration after the initial upsurge. Reducing sugar concentration showed an early upsurge, its contribution to osmotic readjustment being at least equal to that of accumulated Na+, K+ and Cl- the day after stress began. Potassium was preferentially accumulated over sodium into leaves during the first 8 days of the experiment and the sum of these two cations generally balanced accumulating chloride. Except for an initial loss of turgor in vines given 100 mM NaCl, turgor potential was maintained within 0.1 MPa of control plants for all of the treatments throughout the experiment.

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Abscisic acid is essential for rewiring of jasmonic acid-dependent defenses during herbivory

10.1101/747345 ◽

2019 ◽

Cited By ~ 2

Author(s):

Irene A Vos ◽

Adriaan Verhage ◽

Lewis G Watt ◽

Ido Vlaardingerbroek ◽

Robert C Schuurink ◽

...

Keyword(s):

Abscisic Acid ◽

Jasmonic Acid ◽

Plant Hormone ◽

Pieris Rapae ◽

Necrotrophic Pathogen ◽

Plant Insect Interactions ◽

Gcc Box ◽

Insect Interactions ◽

And Control

AbstractJasmonic acid (JA) is an important plant hormone in the regulation of defenses against chewing herbivores and necrotrophic pathogens. In Arabidopsis thaliana, the JA response pathway consists of two antagonistic branches that are regulated by MYC- and ERF-type transcription factors, respectively. The role of abscisic acid (ABA) and ethylene (ET) in the molecular regulation of the MYC/ERF antagonism during plant-insect interactions is still unclear. Here, we show that production of ABA induced in response to leaf-chewing Pieris rapae caterpillars is required for both the activation of the MYC-branch and the suppression of the ERF-branch during herbivory. Exogenous application of ABA suppressed ectopic ERF-mediated PDF1.2 expression in 35S::ORA59 plants. Moreover, the GCC-box promoter motif, which is required for JA/ET-induced activation of the ERF-branch genes ORA59 and PDF1.2, was targeted by ABA. Application of gaseous ET counteracted activation of the MYC-branch and repression of the ERF-branch by P. rapae, but infection with the ET-inducing necrotrophic pathogen Botrytis cinerea did not. Accordingly, P. rapae performed equally well on B. cinerea-infected and control plants, whereas activation of the MYC-branch resulted in reduced caterpillar performance. Together, these data indicate that upon feeding by P. rapae, ABA is essential for activating the MYC-branch and suppressing the ERF-branch of the JA pathway, which maximizes defense against caterpillars.

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