Participation of abscisic acid and gibberellins produced by endophytic Azospirillum in the alleviation of drought effects in maize

Botany ◽  
2009 ◽  
Vol 87 (5) ◽  
pp. 455-462 ◽  
Author(s):  
Ana C. Cohen ◽  
Claudia N. Travaglia ◽  
Rubén Bottini ◽  
Patricia N. Piccoli

Azospirillum spp. are plant growth promoting bacteria (PGPB) that enhance growth by several mechanisms, including the production of phytohormones such as abscisic acid (ABA), indole-3-acetic acid (IAA), and gibberellins (GAs). Their presence may also alleviate plant water stress. In the present paper, the effects of Azospirillum lipoferum in maize ( Zea mays  L.) plants treated with inhibitors of ABA and GA synthesis, fluridone (F) and prohexadione-Ca (P), respectively, and either submitted to drought stress or provided sufficient water, were analysed. Fluridone diminished the growth of plants that had been well watered, in a manner similar to drought, but inoculation with Azospirillum completely reversed this effect. The relative water content of the F-treated and drought-stressed plants was significantly lower (even though drought-stressed plants had been allowed to recover for one week), and this effect was completely neutralized by Azospirillum. These results were correlated with ABA levels assessed by GC-EIMS. Growth was diminished in drought-submitted plants treated with P, alone or combined with F, even though ABA levels were enhanced, suggesting that GAs produced by the bacterium are also important in stress alleviation. The results suggest that both ABA and GAs contribute to water-stress alleviation of plants by Azospirillum.

2020 ◽  
Vol 53 (2) ◽  
Author(s):  
Muhammad Mubeen ◽  
Asghari Bano ◽  
Barkat Ali ◽  
Zia Ul Islam ◽  
Ashfaq Ahmad ◽  
...  

Author(s):  
Gisselle Perez Machado ◽  
Gisselle Perez Machado ◽  
Juan G Colli Mull ◽  
Guillermin Aguero Chapin ◽  
Gustavo A de la Riva de la Riva ◽  
...  

2021 ◽  
Author(s):  
Daniel Palberg ◽  
Anna Kisiała ◽  
Gabriel Lemes Jorge ◽  
R. J. Neil Emery

Abstract BackgroundSymbiotic Methylobacterium strains comprise a significant part of plant microbiomes. Their presence enhances plant productivity and stress resistance, prompting classification of these strains as plant growth-promoting bacteria (PGPB). Methylobacteria can synthesize unusually high levels of plant hormones, called cytokinins (CKs), including the most active form, trans-Zeatin (tZ). ResultsThis study provides a comprehensive inventory of 46 representatives of Methylobacterium genus with respect to phytohormone production in vitro, including 16 CK forms, abscisic acid (ABA) and indole-3-acetic acid (IAA). High performance-liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) analyses revealed varying abilities of Methylobacterium strains to secrete phytohormones that ranged from 5.09 to 191.47 pmol mL-1 for total CKs, and 0.46 to 82.16 pmol mL-1 for tZ. Results indicate that reduced methanol availability, the sole carbon source for bacteria in the medium, stimulates CK secretion by Methylobacterium. Additionally, select strains were able to transform L-tryptophan into IAA while no ABA production was detected.ConclusionsTo better understand features of CKs in plants, this study uncovers CK profiles of Methylobacterium that are instrumental in microbe selection for effective biofertilizer formulations.


2010 ◽  
Vol 33 (1) ◽  
pp. 203-209 ◽  
Author(s):  
D. Saravanakumar ◽  
M. Kavino ◽  
T. Raguchander ◽  
P. Subbian ◽  
R. Samiyappan

2020 ◽  
Vol 10 (20) ◽  
pp. 7025
Author(s):  
Slimane Mokrani ◽  
El-hafid Nabti ◽  
Cristina Cruz

Humanity in the modern world is confronted with diverse problems at several levels. The environmental concern is probably the most important as it threatens different ecosystems, food, and farming as well as humans, animals, and plants. More specifically, salinization of agricultural soils is a global concern because of on one side, the permanent increase of the areas affected, and on the other side, the disastrous damage caused to various plants affecting hugely crop productivity and yields. Currently, great attention is directed towards the use of Plant Growth Promoting Bacteria (PGPB). This alternative method, which is healthy, safe, and ecological, seems to be very promising in terms of simultaneous salinity alleviation and improving crop productivity. This review attempts to deal with different aspects of the current advances concerning the use of PGPBs for saline stress alleviation. The objective is to explain, discuss, and present the current progress in this area of research. We firstly discuss the implication of PGPB on soil desalinization. We present the impacts of salinity on crops. We look for the different salinity origin and its impacts on plants. We discuss the impacts of salinity on soil. Then, we review various recent progress of hemophilic PGPB for sustainable agriculture. We categorize the mechanisms of PGPB toward salinity tolerance. We discuss the use of PGPB inoculants under salinity that can reduce chemical fertilization. Finally, we present some possible directions for future investigation. It seems that PGPBs use for saline stress alleviation gain more importance, investigations, and applications. Regarding the complexity of the mechanisms implicated in this domain, various aspects remain to be elucidated.


2017 ◽  
Vol 39 (2) ◽  
Author(s):  
GLEIKA LARISSE OLIVEIRA DORASIO DE SOUZA ◽  
DEIVISSON FERREIRA DA SILVA ◽  
SILVIA NIETSCHE ◽  
ADELICA APARECIDA XAVIER ◽  
MARLON CRISTIAN TOLEDO PEREIRA

ABSTRACT The use of bio-fertilizers and microbial inoculants that promote plant growth and increased yield has been accepted as an alternative to reduce the use of chemical fertilizers. The objective of the present study was to evaluate the effect of plant growth promoting bacteria inoculation on growth and quality of micropropagated banana seedlings ‘Prata Anã’. The experimental design was completely randomized, with four replications and the treatments consisted of 24 isolates of endophytic bacteria. The isolates EB-50 (Bacillus sp.) and EB-133 (Bacillus amyloliquefaciens) characterized as diazotrophic, the EB-51 (Bacillus pumilus) indicate for inorganic phosphate solubilization and EB-55(Bacillus subtilis) and EB-40 (Bacillus sp.) indole-3-acetic acid producers have provided significant increases for length, pseudostem diameter, fresh masses and dry masses in ‘Prata Anã’ micropropagated banana seedlings.


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