Applied abscisic acid, root growth and turgor pressure responses of roots of wild-type and the ABA-deficient mutant, Notabilis, of tomato

1997 ◽  
Vol 151 (1) ◽  
pp. 60-62 ◽  
Author(s):  
A. Griffiths ◽  
H.G. Jones ◽  
A.D. Tomos
2016 ◽  
Vol 61 (3) ◽  
pp. 328-339 ◽  
Author(s):  
Xiangnan Li ◽  
Dun-Xian Tan ◽  
Dong Jiang ◽  
Fulai Liu

Author(s):  
D. S. Syrova ◽  
V. Y. Shakhnazarova ◽  
A. I. Shaposhnikov ◽  
A. A. Belimov ◽  
Y. V. Gogolev

The intensity of root colonization by phytopathogenic fungus and rhizobacterium differs depending on the tomato genotype. Inoculation of wild-type tomatoes Ailsa Craig, but not of its ABA deficient mutant flacca, with Novosphingobium sp. P6W inhibits root colonization by Fusarium oxysporum MF-G284.


2021 ◽  
Vol 2(26) ◽  
pp. 28-40
Author(s):  
Z.A. Akhtyamova ◽  
◽  
T.N. Arkhipova ◽  
E.V. Martynenko ◽  
T.V. Nuzhnaya ◽  
...  

The ability to produce phytohormones and influence their metabolism in plants is an important property of rhizosphere bacteria that determines their plant growth promoting effect. Since abscisic acid (ABA) reduces stomatal conductance and increases the ability of tissues to conduct water, maintenance of water balance in lettuce plants on the background of activation of their growth was associated with the accumulation of ABA under the influence of bacteria. The aim of the study is to test the hypothesis that the growth-stimulating effect of bacteria on plants depends on their ability to synthesize the hormone ABA. The plants were grown on a light platform; seedlings were treated with a bacterial suspension simultaneously with planting. The ABA content, the relative water content, the chlorophyll content, the level of non-photochemical quenching, the leaf area and the weight of the shoots were measured. The level of transcripts of the HvNCED1, HvNCED2, and HvCYP707A1 genes responsible for ABA metabolism in barley was assessed using real-time PCR. Comparison of the ABA-deficient mutant of barley and plants of its wild type revealed the stimulation of the growth of plants of both genotypes upon bacterial treatment. The shoot mass and leaf area of the untreated mutant with bacteria were about 30 % less compared to Steptoe. The stimulating effect of bacteria was manifested in an increase in leaf area by 15 % in Steptoe and by 35 % in Az 34; shoot mass – by 18 % and 41 %, respectively. As a result, the phenotype difference between plants of two genotypes decreased. In the deficient mutant, the ABA level increased under the influence of Bacillus subtilis IB-22 more than twice. It was due to the ability of bacteria to produce ABA and reduce the activity of ABA degradation in barley plants. The results obtained in this study indicate that certain bacterial strains are able to increase the level of ABA in plants, compensating for the genetically determined deficiency of this hormone.


HortScience ◽  
2009 ◽  
Vol 44 (7) ◽  
pp. 1890-1894 ◽  
Author(s):  
Mason T. MacDonald ◽  
Rajasekaran R. Lada ◽  
Jeff Hoyle ◽  
A. Robin Robinson

Ambiol, a derivative of 5-hydroxybenzimidazole, has been well documented to function as a growth promoter, an antistress compound, and an antioxidant when applied as a seed preconditioning agent. However, evidence suggests that Ambiol decreases transpiration and promotes root growth similar to the phytohormone abscisic acid (ABA), leading to the development of the hypothesis that Ambiol promotes drought resistance through an ABA-dependent pathway. The effect of 0 mg·L−1 and 10 mg·L−1 was tested on wild-type tomato seedlings (Lycopersicon esculentum Mill. var. Scotia), ABA-deficient flacca tomato seedlings, and ABA-inhibited (with fluridone) tomato seedlings. In both fluridone-treated and flacca seedlings, Ambiol preconditioning resulted in significant increases in shoot growth, root growth, leaf area, and plant height consistent with gains experienced by wild-type tomatoes. In addition, flacca tomatoes experienced increases in photosynthesis and water use efficiency consistent with wild-type tomatoes. Ambiol was able to confer benefits to drought-stressed tomatoes in ABA-deficient and ABA-inhibited conditions, suggesting that Ambiol functions through an ABA-independent pathway.


2019 ◽  
Vol 65 (No. 10) ◽  
pp. 516-521 ◽  
Author(s):  
Zhiyu Zuo ◽  
Junhong Guo ◽  
Caiyun Xin ◽  
Shengqun Liu ◽  
Hanping Mao ◽  
...  

Salt acclimation is a process to enhance salt tolerance in plants. The salt acclimation induced salt tolerance was investigated in a spring barley (Hordeum vulgare L.) cv. Steptoe (wild type, WT) and its abscisic acid (ABA)-deficient mutant Az34. Endogenesis ABA concentration in leaf was significantly increased by salt stress in WT, while it was not affected in Az34. Under salt stress, the salt acclimated Az34 plants had 14.8% lower total soluble sugar concentration and 93.7% higher sodium (Na) concentration in leaf, compared with salt acclimated WT plants. The acclimated plants had significantly higher leaf water potential and osmotic potential than non-acclimated plants in both WT and Az34 under salt stress. The salt acclimation enhanced the net photosynthetic rate (by 22.9% and 12.3%) and the maximum quantum yield of PS II (22.7% and 22.0%) in WT and Az34 under salt stress. However, the stomatal conductance in salt acclimated Az34 plants was 28.9% lower than WT under salt stress. Besides, the guard cell pair width was significantly higher in salt acclimated Az34 plants than that in WT plants. The results indicated that the salt acclimated WT plants showed a higher salt tolerance than Az34 plants, suggesting that ABA deficiency has a negative effect on the salt acclimation induced salt tolerance in barley.


2021 ◽  
Vol 7 (12) ◽  
pp. eabd4113
Author(s):  
Rui Miao ◽  
Wei Yuan ◽  
Yue Wang ◽  
Irene Garcia-Maquilon ◽  
Xiaolin Dang ◽  
...  

The hab1-1abi1-2abi2-2pp2ca-1 quadruple mutant (Qabi2-2) seedlings lacking key negative regulators of ABA signaling, namely, clade A protein phosphatases type 2C (PP2Cs), show more apoplastic H+ efflux in roots and display an enhanced root growth under normal medium or water stress medium compared to the wild type. The presence of low ABA concentration (0.1 micromolar), inhibiting PP2C activity via monomeric ABA receptors, enhances root apoplastic H+ efflux and growth of the wild type, resembling the Qabi2-2 phenotype in normal medium. Qabi2-2 seedlings also demonstrate increased hydrotropism compared to the wild type in obliquely-oriented hydrotropic experimental system, and asymmetric H+ efflux in root elongation zone is crucial for root hydrotropism. Moreover, we reveal that Arabidopsis ABA-insensitive 1, a key PP2C in ABA signaling, interacts directly with the C terminus of Arabidopsis plasma membrane H+-dependent adenosine triphosphatase 2 (AHA2) and dephosphorylates its penultimate threonine residue (Thr947), whose dephosphorylation negatively regulates AHA2.


Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1247-1255 ◽  
Author(s):  
Eiji Nambara ◽  
Masaharu Suzuki ◽  
Suzanne Abrams ◽  
Donald R McCarty ◽  
Yuji Kamiya ◽  
...  

Abstract The plant hormone abscisic acid (ABA) controls many aspects of plant growth and development under a diverse range of environmental conditions. To identify genes functioning in ABA signaling, we have carried out a screen for mutants that takes advantage of the ability of wild-type Arabidopsis seeds to respond to (−)-(R)-ABA, an enantiomer of the natural (+)-(S)-ABA. The premise of the screen was to identify mutations that preferentially alter their germination response in the presence of one stereoisomer vs. the other. Twenty-six mutants were identified and genetic analysis on 23 lines defines two new loci, designated CHOTTO1 and CHOTTO2, and a collection of new mutant alleles of the ABA-insensitive genes, ABI3, ABI4, and ABI5. The abi5 alleles are less sensitive to (+)-ABA than to (−)-ABA. In contrast, the abi3 alleles exhibit a variety of differences in response to the ABA isomers. Genetic and molecular analysis of these alleles suggests that the ABI3 transcription factor may perceive multiple ABA signals.


1982 ◽  
Vol 37 (9) ◽  
pp. 793-801 ◽  
Author(s):  
Rudolf Karl ◽  
Wolfhart Rüdiger

Extracts from oat husks inhibit germination of a variety of seeds including Avena sativa L., Sorghum spec., Phalleris spec., Raphanus spec., Amaranthus caudatus, Lepidium sativum L. A quantitative assay for this inhibition was developed on the basis of percentage of root growth of Avena in the presence of extracted material compared with root growth of water controls. Fractionation of the extracts revealed that about half of the total inhibitory activity was found in the fraction of free organic acids. The inhibition was not due to known inhibitors. Abscisic acid. was not found in this extract. Phenole carbonic acids were determined in the extract. Their con­centration was too low to significantly contribute to the observed inhibitory activity.


2000 ◽  
Vol 182 (23) ◽  
pp. 6707-6713 ◽  
Author(s):  
Eve-Ly Ojangu ◽  
Andres Tover ◽  
Riho Teras ◽  
Maia Kivisaar

ABSTRACT The main sigma factor activating gene expression, necessary in stationary phase and under stress conditions, is ςS. In contrast to other minor sigma factors, RNA polymerase holoenzyme containing ςS (EςS) recognizes a number of promoters which are also recognized by that containing ς70 (Eς70). We have previously shown that transposon Tn4652 can activate silent genes in starvingPseudomonas putida cells by creating fusion promoters during transposition. The sequence of the fusion promoters is similar to the ς70-specific promoter consensus. The −10 hexameric sequence and the sequence downstream from the −10 element differ among these promoters. We found that transcription from the fusion promoters is stationary phase specific. Based on in vivo experiments carried out with wild-type and rpoS-deficient mutant P. putida, the effect of ςS on transcription from the fusion promoters was established only in some of these promoters. The importance of the sequence of the −10 hexamer has been pointed out in several published papers, but there is no information about whether the sequences downstream from the −10 element can affect ςS-dependent transcription. Combination of the −10 hexameric sequences and downstream sequences of different fusion promoters revealed that ςS-specific transcription from these promoters is not determined by the −10 hexameric sequence only. The results obtained in this study indicate that the sequence of the −10 element influences ςS-specific transcription in concert with the sequence downstream from the −10 box.


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