Growth Enhancement and Disease Reduction of Soybean by 1-Aminocyclopropane-1-Carboxylate Deaminase-Producing <i>Pseudomonas</i>

Abstract

Problem statement: 1-Aminocyclopropane-1-Carboxylate (ACC) deaminase-producing bacteria have been known to ameliorate the inhibition-effect of increase concentration of ethylene in higher plants, which can be triggered by high concentration of indole-3-Acetic Acid (IAA) and/or by the presence of plant pathogens. This study examined the potential use of Pseudomonas isolates producing ACC deaminase as well as IAA to enhance soybean growth and reduce disease incidence in soil containing pathogenic fungi. Approach: Eleven promising ACC deaminase-producing isolates of Pseudomonas were retested in vitro for their ACC deaminase activity and IAA production and evaluated their potential antagonist against root-nodule bacteria. Non antagonist isolates were further tested for their ability to enhance soybean growth and reduce disease incidence in sterile and non-sterile soils containing root-pathogenic fungi Fusarium oxysporum, Sclerotium rolfsii and Rhizoctonia solani. Results: All isolates produced ACC deaminase as well as IAA, but 3 out of 11 isolates inhibited at least one strain of rhizobia which limit their use for soybean. The isolates increased some aspects of soybean growth, but most of the increases were not significantly different from untreated control. Most isolates significantly increased the survival rates of soybean in soil containing pathogenic fungi although their ability to reduce plant weight loss varied across pathogen treatments. Conclusion: The ability of Pseudomonas producing ACC deaminase as well as IAA to increase plant growth was less significant than that of the isolates to reduce disease incidence. The higher the destructive effect of the pathogens, the better was the ability of the isolates to reduce the disease.

P-Solubilizing Streptomyces roseocinereus MS1B15 With Multiple Plant Growth-Promoting Traits Enhance Barley Development and Regulate Rhizosphere Microbial Population

“…As other bacterial genera living in the soil including Pseudomonas (Hall et al, 1996), Enterobacter (Li et al, 2000), and Bacillus (Ghosh et al, 2003) were able to produce ACC, also the strain S. roseocinereus MS1B15 was able to grow on DF agar medium amended with ACC as the sole nitrogen source. This is an interesting ability because ACC deaminase-producing bacteria have been known to promote plant growth by decreasing ethylene inhibition of various plant processes (Husen et al, 2011).…”

Evaluation of antagonistic activities against Pythium myriotylum and plant growth promoting traits of Streptomyces isolated from Cocoyam (Xanthosoma sagittifolium (L.) Schott) rhizosphere

“…Therefore, they are ideal for use as biocontrol agents since the rhizosphere provides the front line defense for roots against attack by pathogen (Gracia et al, 2001;Maleki et al, 2010). The three selected isolates were screened for different PGP traits such as phosphate solubilisation, siderophore production, IAA synthesis, ammonia (NH3), HCN and lower ethylene plant levels by synthetizing 1-aminocyclopropane-1carboxylate (ACC) deaminase activity and were found to be showing excellent PGP activities (Husen et al, 2011;Passari et al, 2015;Nguyen et al, 2016). Among some beneficial rhizosphere microorganisms, Streptomyces are mainly known to stimulate the growth of several annual crops.…”

Biological control potential of rhizosphere bacteria with ACC-deaminase activity against Fusarium culmorum in wheat

“…As an alternative to synthetic fungicides, biological control of pathogens including the use of ACC-deaminase producing plant growth-promoting bacteria has been an emphasis in the plant protection studies (Glick, 2014). Pre-treatment of plants with ACC-deaminase containing plant growth-promoting bacteria can provide significant protection to plants against some of the ethylene caused damage from pathogen infection as well as water stress (Husen et al, 2011;Amutharaj et al, 2012;Nascimento et al, 2013). However, the available biocontrol agents in some cases fail in the field.…”