Revealing the nano-architecture of plant cell wall using 3D coherent diffractive imaging

• Grant number: 20/13748-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): January 01, 2022
• Effective date (End): August 31, 2024
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Florian Edouard Pierre Meneau
• Grantee: Francine Faia Fernandes
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Associated research grant: 14/25964-5 - From the monomers to the nanoparticles: in situ real time investigation of gold nanoparticles formation by synchrotron and microscopy techniques, AP.JP

Abstract

Plant cell walls are plastic structures with a physiological role of protection against pathogens and the environment. The cell wall is a lignin rich matrix and this aromatic polymer represents the main bottleneck to the efficient conversion of polysaccharides into fermentable sugars to produce biofuels and bioproducts. Genetic Engineering holds great promise to generate plants with lower lignin levels or altered lignin structures, decreasing biomass recalcitrance to degradation and improving hydrolysis rates. On the other hand, the reduction of the endogenous lignin content can be accompanied by negative effects on plant growth and development, making the commercial exploitation of such manipulated plants a challenge. Lignin metabolism research is a fertile field to be explored in terms of cell wall structure understanding, which has been, so far, poorly explored. We pioneered three-dimensional coherent diffraction imaging applied to plant science using cryo-ptychography. We showed how the hierarchical structure of vegetal tissue can be imaged and explored from the nanometric to the 10s of microns scales. We propose here to explore the nano structure of sorghum and S. viridis wild-type and mutant/transgenic cell walls. The synchrotron coherent imaging experiments will be conducted at the Cateretê beamline (Sirius 4th generation synchrotron source, Campinas) where we are installing a cryo experimental station dedicated to radiation sensitive specimen. The latter setup will offer unprecedent capabilities to perform nano-imaging of cells and soft tissues using the Coherent X-ray Diffractive Imaging (CXDI). To achieve this goal, two main technical aspects will be covered to during this project, comprising, first, the proposition of a novel sample preparation workflow at cryogenic conditions to prepare microfragments of tissues and avoid radiation damage and, second, the analysis workflow for large datasets within the volumetric images, using HPCs, to guarantee that the data the will be accurately extracted and acquired in a reasonable time. Finally, we will be able to quantify and characterize morphological dissimilarities in the lignin deficient plants and compare to the wild-type plants to better understand physiological processes aiming at a rational engineering of grasses biomass for industrial applications. (AU)