Gluconacetobacter diazotrophicus Pal5 Enhances Plant Robustness Status under the Combination of Moderate Drought and Low Nitrogen Stress in Zea mays L.

Abstract

Plant growth promoting endophytic bacteria, which can fix nitrogen, plays a vital role in plant growth promotion. Previous authors have evaluated the effect of Gluconacetobacter diazotrophicus Pal5 inoculation on plants subjected to different sources of abiotic stress on an individual basis. The present study aimed to appraise the effect of G. diazotrophicus inoculation on the amelioration of the individual and combined effects of drought and nitrogen stress in maize plants (Zea mays L.). A pot experiment was conducted whereby treatments consisted of maize plants cultivated under drought stress, in soil with a low nitrogen concentration and these two stress sources combined, with and without G. diazotrophicus seed inoculation. The inoculated plants showed increased plant biomass, chlorophyll content, plant nitrogen uptake, and water use efficiency. A general increase in copy numbers of G. diazotrophicus, based on 16S rRNA gene quantification, was detected under combined moderate stress, in addition to an increase in the abundance of genes involved in N fixation (nifH). Endophytic colonization of bacteria was negatively affected by severe stress treatments. Overall, G. diazotrophicus Pal5 can be considered as an effective tool to increase maize crop production under drought conditions with low application of nitrogen fertilizer.

Phenylalanine Ammonia-Lyase (PAL) Genes Family in Wheat (Triticum aestivum L.): Genome-Wide Characterization and Expression Profiling

“…This might be due to the presence of Cis elements [16]. Similarly, GdPAL5 is also reported to be an auxin producer which activates plant defense mechanisms during the abiotic stress [83]. Different gene family members usually display abundance disparities in different tissues or under distinct stresses [84].…”

Endophytic bacteria perform better than endophytic fungi in improving plant growth under drought stress: A meta‐comparison spanning 12 years (2010–2021)

“…The extent of plant adaptation to drought stress is often measured by increases in plant biomass (Dastogeer, Chakraborty, et al, 2020a; Munns, 2002; Tufail, Touceda‐González, et al, 2021b). Indeed, our meta‐analysis revealed that EB and EF inoculation increased biomass output, which is consistent with prior findings (Dastogeer, Chakraborty, et al, 2020a; Dubey et al, 2021; Rho et al, 2018; Zhang et al, 2020).…”

“…The extent of plant adaptation to drought stress is often measured by increases in plant biomass (Dastogeer, Chakraborty, et al, 2020a;Munns, 2002;Tufail, Touceda-González, et al, 2021b).…”

“…However, most of these traditional and modern approaches are either time-consuming, energy-intensive or demand a high level of expertise, such as genetic engineering. Under these circumstances, the trend of mitigating the effects of abiotic stresses on plants by developing plant-endophyte relationships has been rising considerably, as observed by recently published studies (Porter et al, 2020;Santoyo et al, 2016;Tufail, Bejarano, et al, 2021a;Tufail, Touceda-González, et al, 2021b). Particularly in the last decade, a huge intent was shown by researchers to tackle drought stress by using endophytic bacterial and fungal bio-inoculation in crop plants.…”

Can Bacterial Endophytes Be Used as a Promising Bio-Inoculant for the Mitigation of Salinity Stress in Crop Plants?—A Global Meta-Analysis of the Last Decade (2011–2020)

“…Among all plant-associated bacteria, endophytes show to relive the impacts of salt stress in plants by inducing osmotic adjustment, detoxification, modulation of phytohormones, and acquisition of nutrients [ 17 , 18 , 19 ]. Endophytic bacteria with 1-aminocylopropane−1-carboxylate (ACC) deaminase and indole−3-acetic acid (IAA) production, nitrogen fixation, phosphate solubilization, and siderophore production traits have shown to promote the osmotic or ionic adaptation of host plants [ 20 , 21 , 22 , 23 , 24 ]. However, the exact endophytic bacterial-mediated mechanisms underlying salt stress alleviation remain largely unknown [ 25 ].…”