Exogenous Bio-Based 2,3-Butanediols Enhanced Abiotic Stress Tolerance of Tomato and Turfgrass under Drought or Chilling Stress

Abstract

Bacteria with plant growth-promoting activity belong to several genera, including Azotobacter, Bacillus, Klebsiella, Pseudomonas,. The functional mechanisms of PGPR are varied and include the ability to change hormone content, produce volatile compounds, promote nutrient availability, or enhance abiotic stress tolerance [12]. Interactions between plants and rhizosphere microbes are known to increase tolerance to drought directly or indirectly [13]. Among PGPR, several bacteria, including Bacillus and Klebsiella, produce volatile organic compounds, such as 2,3-butanediol (2,3-BDO), which are known to induce plant systemic resistance against phytopathogens and can also enhance tolerance to abiotic stresses in plants [14].Among abiotic stresses in plants, drought and chilling stresses reduce the supply of moisture to plant tissues, inhibit photosynthesis, and severely reduce plant growth and yield. Thus, the application of water stress-tolerant agents can be a useful strategy to maintain plant growth under abiotic stresses. This study assessed the effect of exogenous bio-based 2,3-butanediol (BDO) application on drought and chilling response in tomato and turfgrass, and expression levels of several plant signaling pathway-related gene transcripts. Bio-based 2,3-BDOs were formulated to levo-2,3-BDO 0.9% soluble concentrate (levo 0.9% SL) and meso-2,3-BDO 9% SL (meso 9% SL). Under drought and chilling stress conditions, the application of levo 0.9% SL in creeping bentgrass and meso 9% SL in tomato plants significantly reduced the deleterious effects of abiotic stresses. Interestingly, pretreatment with levo-2,3-BDO in creeping bentgrass and meso-2,3-BDO in tomato plants enhanced JA and SA signaling pathway-related gene transcript expression levels in different ways. In addition, all tomato plants treated with acibenzolar-S-methyl (as a positive control) withered completely under chilling stress, whereas 2,3-BDO-treated tomato plants exhibited excellent cold tolerance. According to our findings, bio-based 2,3-BDO isomers as sustainable water stress-tolerant agents, levo-and meso-2,3-BDOs, could enhance tolerance to drought and/or chilling stresses in various plants through somewhat different molecular activities without any side effects.

Exploring the Biologically Active Metabolites Produced by Bacillus cereus for Plant Growth Promotion, Heat Stress Tolerance, and Resistance to Bacterial Soft Rot in Arabidopsis

“…Additionally, the BcD1genome contained six genes for synthesis of bacillibactin, a catechol-type siderophore, and three genes for synthesis of spermidine, a polyamine, which is a component of biofilm [ 66 , 67 ]. Microbial metabolites, including VOCs, siderophores, and biofilm components, have multifaceted functions in plant growth by suppressing pathogen growth and activating plant defense response [ 7 , 68 , 69 ]. Ten genes were identified in the BcD1 genome that encode two types of serine proteases: subtilisin-like serine proteases (subtilases) and trypsin-like serine proteases.…”

Do Volatiles Affect Bacteria and Plants in the Same Way? Growth and Biochemical Response of Non-Stressed and Cd-Stressed Arabidopsis thaliana and Rhizobium E20-8

“…2,3-Butanediol from the leachates of pine needles activated the resistance of Panax notoginseng to leaf disease infection through ISR and camalexin biosynthesis [ 63 ]. In tomato plants, 2,3-butanediol enhanced the transcription of jasmonic acid and salicylic acid responsive genes, increasing tolerance to drought and chilling stress [ 64 ]. In our study, 2,3-butanediol also promoted A. thaliana growth and had an antioxidant effect at lower concentrations, protecting membranes from damage (LPO decrease) and decreasing antioxidant enzyme activity (SOD and GPx) and cell metabolism (lower soluble protein levels).…”