The oxalyl‐CoA synthetase‐regulated oxalate and its distinct effects on resistance to bacterial blight and aluminium toxicity in rice

Abstract

ABSTRACT• Oxalic acid is widely distributed in biological systems and known to play functional roles in plants. The gene AAE3 was recently identified to encode an oxalyl-CoA synthetase (OCS) in Arabidopsis that catalyses the conversion of oxalate and CoA into oxalyl-CoA. It will be particularly important to characterise the homologous gene in rice since rice is not only a monocotyledonous model plant, but also a staple food crop.• Various enzymatic and biological methods have been used to characterise the homologous gene.• We first defined that AAE3 in the rice genome (OsAAE3) . Chemical modification and site-directed mutagenesis analyses identified thiols as the active site residues for rice OCS catalysis, suggesting that the enzyme might be regulated by redox state. Subcellular localisation assay showed that the enzyme is located in the cytosol and predominantly distributed in leaf epidermal cells. As expected, oxalate levels increased when OCS was suppressed in RNAi transgenic plants. More interestingly, OCS-suppressed plants were more susceptible to bacterial blight but more resistant to Al toxicity.• The results demonstrate that the OsAAE3-encoded protein also acts as an OCS in rice, and may play different roles in coping with stresses. These molecular, enzymatic and functional data provide first-hand information to further clarify the function and mechanism of OCS in rice plants.

Identification of oxalyl-CoA synthetase gene (LsAAE3) and its regulatory role in β-ODAP biosynthesis in grasspea (Lathyrus sativusL.)

“…The Acyl Activating Enzyme 3 ( AAE3 ) gene was first time discovered to function as an oxalyl-CoA synthetase in Arabidopsis thaliana (Foster et al 2012). Later on, the AAE3 ortholog was reported in the budding yeast Saccharomyces cerevisiae (Foster and Nakata 2014), model legume Medicago truncatula (Foster et al 2016), rice bean (Lou et al 2016) and rice (Peng et al 2017). In all these non-ODAP forming plant species, oxalyl-CoA synthetase enzyme was reported to be involved in proposed multi-step oxalate degradation pathway (Foster et al, 2012; Giovanelli and Tobin; Fig.…”

Time Series RNA-seq in Pigeonpea Revealed the Core Genes in Metabolic Pathways under Aluminum Stress

“…The secondary metabolites produced in plants are important substances in the process of plant growth and development. Under the interactions between phosphorus and aluminum, the adenosine triphosphate (ATP) and adenylate energy charge (AEC) levels are significantly changed and have an effect on the anaplerotic metabolism of root zone CO 2 [6].Aluminum in soil not only affects plants in special areas, such as pigeonpea, but is also found in the growing environment of many crops, such as rice and tomato [6,[12][13][14]. Additionally, Arabidopsis, as a model plant, has also provided a research basis for Al stress [15][16][17].…”

“…In addition to Al stress, there is also bacterial invasion. In rice and Arabidopsis, the regulation of resistance to bacterial and aluminum toxicity has been found to respond to Al and bacterial regulation at the same time [14,15].The availability of high-throughput sequencing technologies [18] and the completion of a draft genome of pigeonpea [19][20][21] make it possible to rapidly detect transcriptional changes in pigeonpea. Differential gene expression analysis is often used to study developmental and stress-related regulations.…”

“…Aluminum in soil not only affects plants in special areas, such as pigeonpea, but is also found in the growing environment of many crops, such as rice and tomato [6,[12][13][14]. Additionally, Arabidopsis, as a model plant, has also provided a research basis for Al stress [15][16][17].…”

“…In addition to Al stress, there is also bacterial invasion. In rice and Arabidopsis, the regulation of resistance to bacterial and aluminum toxicity has been found to respond to Al and bacterial regulation at the same time [14,15].…”