Wheat (Triticum aestivum L.) growth enhancement by Azospirillum sp. under drought stress

Abstract

Plant growth promoting rhizobacteria (PGPR) can enhance plant growth by alleviating soil stresses. Although previously investigated, some new interesting details are presented regarding the alleviating affects of Azospirillum sp. on wheat growth under drought stress in this research work. We hypothesized that the isolated strains of Azospirillum sp. may alleviate the adverse effects of drought stress on wheat (Triticum aestivum L.) growth. Three different strains of Azospirillum lipoferum (B1, B2 and B3) were used to inoculate wheat seedlings under drought. During the flowering stage the seedlings were subjected to three drought levels with five different time longevity, including control. Pots were water stressed at 80% (S0), 50% (S1) and 25% (S2) of field capacity moisture in a 25 day-period. Soil and plant water properties including water potential and water content, along with their effects on bacterial inoculum and wheat growth, were completely monitored during the experiment. While stress intensity significantly affected bacterial population and wheat growth, stress longevity only affected wheat water potential and water content. Compared to uninoculated treatments strain B3 (fixing and producing the highest amounts of N and auxin, respectively, with P solubilizing and ACC-deaminase activities) increased wheat yield at S1 and S2 by 43 and 109%, respectively. However, strain B2 (producing siderophore) was the most resistant strain under drought stress. The results of this experiment may elucidate the more efficient strains of Azospirillum sp. for wheat inoculation under drought stress and the mechanisms by which they alleviate the stress.

Survey of Plant Drought-Resistance Promoting Bacteria from Populus euphratica Tree Living in Arid Area

“…In the other hand, the better development of plant root under drought stress after inoculation indicate the auxin production of bacteria should have increased but is still within the dose range beneficial for root development. We also investigated the production of both siderophore and acetoin which are also believed to be beneficial for drought resistance for host plants [25]. We observed that acetoin-producing bacteria also had beneficial effects on plant growth and drought resistance in wheat as strains 6-2, 6-7 and 6-12 did dramatically improve plant dry weight and root area.…”

The Role of Soil Beneficial Bacteria in Wheat Production: A Review

“…Drought/water Azospirillum brasilense Sp245 Wheat, growth rate of coleoptiles [132] Drought Azospirillum brasilense INTA Az-39 wheat roots Wheat (T. aestivum) [133] Drought Azospirillum lipoferum Wheat (T. aestivum L.) [134] Drought Burkholderia phytofirmans Wheat (T. aestivum) Grain yield, photosynthetic rate, water use efficiency, chlorophyll content [135] Drought…”

“…According to Arzanesh et al results, inoculation of wheat with Azospirillum spp. can alleviate drought stress on plant growth and yield through adjusting plant water characters [134].…”

Improvement of Rice Growth and Productivity Through Balance Application of Inorganic Fertilizer and Biofertilizer in Inceptisol Soil of Lowland Swamp Area

“…As reported in Saxena and Tilak (1998), Yasari and Patwardhan (2007), Shaukat et al (2006) and Karthikeyan and Sakthivel (2011), bacteria of Azospirillum and Azotobacter could increase crop biomass, crop productivity, which contributed N nutrient through N 2 fixation at crop rhizosphere environment as well as phytohormone in direct manner. Moreover, studies from Yasari and Patwardhan (2007), Mehry et al (2008) and Arzanesh et al (2009) confirmed that application of Azospirillum was very effective in stimulating crop growth. Hindersah and Simarmata (2004) emphasize that Azotobacter bacteria have capability in producing phytohormone of auxin and cytochinine as well as supporting the soil function as growth media.…”