The role of osmotolerant rhizobacteria in rice growth under different drought conditions

Abstract

Osmotolerant rhizobacterial isolates were used as inoculants for rice under different drought conditions in a greenhouse. Rice was grown on a Regosol, under either sterile or non-sterile conditions, in which the water level was adjusted to 80% and 40% of field capacity. Rice seed was inoculated with osmotolerant rhizobacterial isolates (isolates Al-19, A82, and M7b) and grown until the plant reached maximum vegetative phase (86 days from seed sowing). Inocula used were: Al-19 plus A82, Al-19 plus M7b, A82 plus M7b, and a mixture of 3 isolates. Under sterile conditions, inoculation of rice with the different inocula resulted in an increase in shoot dry weight, root dry weight, and number of tillers of 0–45.72%, 0.62–79.67%, and 0– 61.11%, respectively. Under non-sterile condition, shoot dry weight, root dry weight, and number of tillers increased by 19.66–28.04%, 14.00–91.33%, and 14.29–157.14%, respectively. The study also demonstrated that the role of osmotolerant rhizobacteria was more pronounced at 40% field capacity than 80% field capacity.

Amelioration of Drought Stress Adverse Effect and Mediating Biochemical Content of Cabbage Seedlings by Plant Growth Promoting Rhizobacteria

“…PGPRs have been reported to stimulate plant growth regulator accumulation, having a positive effect in plant growth (Bent et al, 2001). GA, SA, IAA production of PGPR can alleviate negative influence of drought stress on cabbage seedlings (Yuwono et al, 2005). Positive effects of PGPR on plant growth can be attributed to their manipulating plant hormone pathways and chnaging plant stress response pathways (Atkinson and Urwin, 2012).…”

Plant–rhizobacteria interactions alleviate abiotic stress conditions

“…2009a), fixation of atmospheric nitrogen (Dobbelaere et al. 2003), enhancement of tolerance to abiotic stresses (Grichko & Glick 2001; Yuwono, Handayani & Soedarsono 2005; Egamberdiyeva 2007; Sziderics et al. 2007; Belimov et al.…”

“…Interestingly, the beneficial effects of inoculation with plant growth‐promoting root zone bacteria have been reported to be most significant under unfavourable conditions such as flooding (Grichko & Glick 2001), drought (Mayak et al. 2004a; Yuwono et al. 2005; Belimov et al.…”

“…1c). Improvement in root proliferation in inoculated drought‐stressed rice plants is likely to be induced by this hormone (Yuwono et al. 2005), apparently for enhanced water uptake.…”

“…Kloepper et al 1999;Chakraborty, Chakraborty & Basnet 2006;Sikora, Schafer & Dababat 2007), enhancement of the bioavailability of minerals in the soil (e.g. Carrillo-Castaneda et al 2003Dimkpa et al 2009a), fixation of atmospheric nitrogen (Dobbelaere et al 2003), enhancement of tolerance to abiotic stresses (Grichko & Glick 2001;Yuwono, Handayani & Soedarsono 2005;Egamberdiyeva 2007;Sziderics et al 2007;Belimov et al 2009;Dimkpa et al 2009a) or stimulation of phytohormone production by the plant (Lazarovits & Nowak 1997).…”