Methylobacterium oryzae CBMB20 influences photosynthetic traits, volatile emission and ethylene metabolism in Oryza sativa genotypes grown in salt stress conditions

Abstract

The objective of this study was to analyze the impact of ACC (1-aminocyclopropane-1carboxylate) deaminase producing Methylobacterium oryzae CBMB20 in acclimation of plant to salt stress by controlling photosynthetic characteristics and volatile emission in salt-sensitive (IR29) and moderately salt resistant (FL478) rice (Oryza sativa L.) cultivars. Saline levels of 50 mM and 100 mM NaCl with and without bacteria inoculation were applied, and the temporal changes in stress response and salinity resistance were assessed by monitoring photosynthetic characteristics, ACC accumulation, ACC oxidase activity (ACO), vacuolar H + ATPase activity and volatile organic compound (VOC) emissions. Salt stress considerably reduced photosynthetic rate, stomatal conductance, PSII efficiency and vacuolar H + ATPase activity, but it increased ACC accumulation, ACO activity, green leaf volatiles (GLV), mono-and sesquiterpenes, and other stress volatiles. These responses were enhanced with increasing salt stress and time. However, rice cultivars treated with CBMB20 showed improved plant vacuolar H + ATPase activity, photosynthetic characteristics and decreased ACC accumulation, ACO activity and VOC emission. The bacteria-dependent changes were greater in the IR29 cultivar. These results indicate that decreasing photosynthesis and vacuolar H + ATPase activity rates and increasing VOC emission rates in response to high salinity stress were effectively mitigated by Methylobacterium oryzae CBMB20 inoculation.

Label‐free proteomics approach reveals candidate proteins in rice (Oryza sativa L.) important for ACC deaminase producing bacteria‐mediated tolerance against salt stress

“…Methylobacterium oryzae CBMB20 has been well documented in enhancing plant growth under salt‐stress conditions through various mechanisms (Madhaiyan et al ., 2007; Chanratana et al ., 2019; Chatterjee et al ., 2019). To determine the GO‐based clustering in rice inoculated with M .…”

“…The differential regulation of the specific proteins important for attaining tolerance against salt stress identified in this study has also been reported previously (Singh et al ., 2017; Zhao et al ., 2021). Likewise, in this study, the abundance of V‐ATPase (Q6EUQ9), which are important proteins for compartmentalizing Na + ions into the vacuole under salt‐stress conditions were increased corroborating previous reports on the V‐ATPase activity enhancement by ACC deaminase producing bacteria (Chatterjee et al ., 2018, 2019).…”

ACC deaminase‐producing Brevibacterium linensRS16 enhances heat‐stress tolerance of rice (Oryza sativa L.)

“…However, the ACO1 expression was significantly lower in heat-stressed plants inoculated with B. linens RS16 than the non-inoculated ones: 0.8-fold decrease at 40 C and 0.7-fold decrease at 45 C. The decrease in ACO1 expression can be attributed to the ability of B linens RS16 to produce ACC deaminase, which can scavenge the precursor of ethylene, ACC, and converts it into α-ketobutyrate and ammonia (Glick 2014;Madhaiyan et al 2006). The modulation of ACC oxidase activity under different environmental stress conditions by ACC deaminase-producing endophytic bacteria has already been reported (Chatterjee et al 2019;Yim et al 2014).…”

Potentials, Utilization, and Bioengineering of Plant Growth-Promoting Methylobacterium for Sustainable Agriculture

“…M. nodulans Crotalaria providing nitrogen; decreasing levels of ethylene [12,16,17] M. oryzae Rice increasing plant cytokinin levels; solubilizing phosphate [13,[18][19][20] M. extorquens Pine; Arabidopsis; Brassia inducing the expression of host defense genes [21,22] M. mesophilicum Sugarcane increasing plant cytokinin levels [23] M. radiotolerans Brassia; Combretaceae providing nitrogen; exhibited high antibacterial and antifungal activity; decreasing levels of ethylene [24,25] M. populi Brassia providing nitrogen [26] M. komagatae Brassia providing nitrogen [17] M. aquaticum Brassia providing nitrogen [17] M. funariae Moss increasing plant cytokinin levels [27] M. phyllosphaerae Rice decreasing levels of ethylene [28]…”