Scientists from Shanghai Chenshan Plant Science Research Center, CAS/ Shanghai Chenshan Botanic Garden and Plant Stress Science Research Center, CAS published their research progress in PeerJ on 13th of June 2019. They used partial defoliation of grass model plant Brachypodium distachyon to explore possible effects of mowing on turf grass in terms of ions accumulation and gene transcription network. The title of their research article is “Partial defoliation of Brachypodium distachyon plants grown in petri dishes under low light increases P and other nutrient levels concomitantly with transcriptional changes in the roots”. Wei Wang from Chenshan Center and Sunil Kumar Singh from PSC are first authors and Dr. Zhaoqing Chu from Chenshan center is the correspondence author.
There have been few studies on the partial defoliation response of grass. It has been unclear how partial defoliation may affect roots at the levels of nutrient accumulation and transcriptional regulation. Hereby we report a comprehensive investigation on molecular impacts of partial defoliation by using a model grass species, B. distachyon.
Our Inductively Coupled Plasma Mass Spectrometry analyses of B. distachyon revealed shoot- and root-specific accumulation patterns of a group of macronutrientsincludingpotassium(K),Phosphorus(P),Calcium(Ca),Magnesium (Mg), and micronutrients including Sodium (Na), iron (Fe), and Manganese (Mn). Meanwhile, our genome-wide proﬁling of gene expression patterns depicts transcriptional impacts on B. distachyon roots by cutting the aerial portion. The RNAseq analyses identiﬁed a total of 1,268 differentially expressed genes in B. distachyon with partial defoliation treatment.
Our comprehensive analyses by means of multiple approaches, including Gene Ontology, InterPro and Pfam protein classification, KEGG pathways, and Plant TFDB, jointly highlight the involvement of hormone-mediated wounding response, primary and secondary metabolites, and ion homeostasis, in B. distachyon after the partial defoliation treatment. In addition, evidence is provided that roots respond to partial defoliation by modifying nutrient uptake and rhizosphere acidication rate, indicating that an alteration of the root/soil interaction occurs in response to this practice. This study reveals how partial defoliation alters ion accumulation levels in shoots and roots, as well as partial defoliation induced transcriptional reprogramming on a whole-genome scale, thereby providing insight into the molecular mechanisms underlying the recovery process of grass after partial defoliation.