Is phosphate solubilizing ability in plant growth‐promoting rhizobacteria isolated from chickpea linked to their ability to produce ACC deaminase?

Abstract

Aims: Since most phosphate solubilizing bacteria (PSB) also produce 1-aminocyclopropane-1-carboxylate (ACC) deaminase, we investigated if there was an association between these two plant growth-promoting properties under in vitro conditions. Methods and Results: A total of 841 bacterial isolates were obtained using selective and enrichment isolation methods. ACC deaminase was investigated using in vitro methods and by sequencing the acdS gene. The effect of ACC deaminase on P solubilization was investigated further using five efficient PSB. ACC deaminase production ability was found amongst a wide range of bacteria belonging to the genera Bacillus, Burkholderia, Pseudomonas and Variovorax. The amount of ACC deaminase produced by PSB was significantly associated with the liberation of Pi from Ca-P when ACC was the sole N source. Ca-P solubilization was associated with the degree of acidification of the medium. Additionally, the P solubilization potential of PSB with (NH 4 ) 2 SO 4 was determined by the type of carboxylates produced. An in-planta experiment was conducted using Burkholderia sp. 12F on chickpea cv. Genesis-863 in sand : vermiculite (1 : 1 v/v) amended with rock phosphate and inoculation of this efficient PSB significantly increased growth, nodulation and P uptake of chickpea fertilized with rock phosphate. Conclusion: ACC deaminase activity influenced the capacity of PSB to solubilize P from Ca-P when ACC was the sole N source and Burkholderia sp. 12F promoted the chickpea-Mesorhizobium symbiosis. Significance and Impact of the Study: ACC deaminase activity could enhance the P solubilizing activity of rhizobacteria that improve plant growth.

Revealing the underlying mechanisms mediated by endophytic actinobacteria to enhance the rhizobia - chickpea (Cicer arietinum L.) symbiosis

“…Recently, a series of research papers have shown that a variety of leguminous plants can form tripartite symbiotic associations with nodule-inducing rhizobia and other plant beneficial microorganisms, such as arbuscular mycorrhiza fungi (AMF), fungal endophyte Phomopsis liquidambari, mineral phosphate-solubilising bacteria, endophytic Bacillus, Methylobacterium oryzae and Micromonospora strains to enhance plant growth, nodulation and N 2 -fixation. (Alemneh et al 2021;Benito et al 2017;Gull et al 2004;Subramanian et al 2015;Wang et al 2011;Zhang et al 2016).…”

Research Advances in the Mutual Mechanisms Regulating Response of Plant Roots to Phosphate Deficiency and Aluminum Toxicity

“…On the other hand, some ACC, an ethylene biosynthesis precursor, is released by the roots and taken up by bacteria, resulting in the expression induction of ACC deaminase. Experimental evidence showed that the amount of ACC deaminase that is produced by phosphate solubilizing bacteria was significantly associated with the liberation of Pi from Ca-P when ACC was the sole N source [133]. Therefore, it appears that PGPR represents a central hub for regulating auxin and ethylene balance to cope with both Al toxicity and P deficiency.…”

Bacterial Diversity Analysis and Screening for ACC Deaminase-Producing Strains in Moss-Covered Soil at Different Altitudes in Tianshan Mountains—A Case Study of Glacier No. 1

“…The three methods mutually confirmed the identification of DY1–3, DY1–4, and EY2–5 as Pseudomonas . The plant-growth-promoting bacteria producing ACC deaminase isolated [ 26 , 27 , 29 , 31 , 32 , 63 , 64 ] at home and abroad are mainly Pseudomonas and Bacillus , which are inseparable from Pseudomonas as indigenous microorganisms in nature (especially in soil), and their ranges of changes in growth temperature and pH value are large. Furthermore, the types of nutrient metabolism are diverse, and Pseudomonas producing ACC deaminase is important in beneficial plant–microorganism interaction [ 26 ].…”