Abstract
AimsWe examined the effect of downregulating PdKOR1 gene, an endo-β-1,4-glucanase gene family member previously characterized to affect cellulose biosynthesis and cell wall composition in Populus, on the secondary metabolome and microbiome of field-grown Populus deltoides.MethodsWe revealed differences in metabolite profiles of PdKOR1 RNAi and control roots using gas chromatography-mass spectrometry, and microbiome identification via Illumina MiSeq 16S and ITS2 rRNA sequencing in root endospheres and rhizospheres.ResultsPdKOR1 RNAi root metabolites differed from control plants: free amino acids (valine, isoleucine, alanine) were reduced while caffeoyl-shikimates, salicylic-acid derivatives, and flavonoid metabolites increased in PdKOR1 RNAi roots. The Actinobacterial family Micromonosporaceae were more abundant in RNAi root endospheres, whereas Nitrospirae was reduced in PdKOR1 RNAi rhizospheres. Ascomycota were lower and Basidiomycota greater in PdKOR1 rhizospheres. Bacterial and fungal community composition, as measured by Bray-Curtis dissimilarity, differed between PdKOR1 RNAi and control rhizospheres and endospheres.ConclusionsThese results indicate that modification of plant cell walls via downregulation of PdKOR1 gene in Populus impacts carbon metabolism in roots and concomitant alterations in root-associated microbial communities. Such an understanding of functional and ecological implications of biomass chemistry improvement efforts is critical to address the goals of sustainable bioenergy crop production and management.
Highlights
Cellulose synthesis and cell wall formation are important processes which regulate plant structure and function
Bacterial and fungal community composition, as measured by Bray-Curtis dissimilarity, differed between PdKOR1 RNAi and control rhizospheres and endospheres. These results indicate that modification of plant cell walls via downregulation of PdKOR1 gene in Populus impacts carbon metabolism in roots and concomitant alterations in root-associated microbial communities
Here we studied the impact of PdKOR1 gene downregulation on the root secondary metabolome and the overall bacterial and fungal microbiomes within the rhizosphere and root endospheres in field-grown Populus deltoides
Summary
Cellulose synthesis and cell wall formation are important processes which regulate plant structure and function. Optimization of plant cell wall and lignocellulosic biomass composition, via genetic modification or selection of cell wall pathway or carbon metabolism genes, are broadly-used strategies in advanced bioenergy feedstock improvement efforts (Fu et al 2011; Kalluri et al 2014; Li et al 2016; Loqué et al 2015; Petersen et al 2012; Yang et al 2013) Such strategies have been demonstrated to achieve shifts in lignin composition (Baxter and Stewart Jr 2013; Furtado et al 2014), cellulose and hemicellulose content (Hernández-Blanco et al 2007; Kalluri et al 2016), and greater hexose:pentose ratios within wood tissue (Loqué et al 2015) with the specific target of improving saccharification of lignocellulosic biomass. For the long-range goal of sustainable production of bioenergy crops, research efforts must co-optimize plants for biomass amount and composition as well as sustainable field performance characteristics such as enhanced water and nutrient-use efficiency, resistance to microbial pathogens, and interactions with beneficial microbes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
