Zdunek, A. | Search bioRxiv

bioRxiv2024

Isolation and characterization of cell wall and extracellular polysaccharides from cultures of the mycoparasitic strain Tirochoderma koningiopsis

The Trichoderma koningiopsis strain showed an extracellular polymers (EPS) synthesis capacity of 1.17 g/L in an optimised Czapek-Dox medium containing sucrose (30 g/L) and yeast extract (7.5 g/L). Three fractions of wall polymers were extracted from the biomass obtained after culture: cold water soluble (WPSZ), hot water soluble (WPSC) and alkali soluble (WPSNaOH), which accounted for 13.3%, 1.8% and 20.2% of the mycelial dry weight, respectively. Structural analyses indicated that the EPS obtained was mannan, and the WPS fractions were glucans containing predominantly [->]4)-Glc-(1[->] linked residues, with branching at [->]3,6)- as well as [->]4,6)-positions. FT-IR and FT-Raman analyses showed that -bonds dominate in the WPSZ and WPSC fractions, whereas {beta}-bonds dominate in the EPS and WPSNaOH fractions. The obtained polymer fractions (PS) showed antioxidant properties in the ABTS, DPPH and FRAP methods and the ability to bind bisphenol A from an aqueous environment. The most important property of the obtained PSs is their ability to reduce germination and inhibit the growth of mycelia of the phytopathogenic Fusarium culmorum strain. The obtained polymers exhibit a number of bioactive properties and can be used in various areas of human life. HighlightsO_LITrichoderma koningiopsis has the ability to synthesise EPS C_LIO_LIEPS are mainly composed of mannose and WPS of glucose C_LIO_LIPS have the ability to chelate BPA and have antioxidant properties C_LIO_LIThe PS obtained has inhibitory properties against F. culmorum. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=151 SRC="FIGDIR/small/605896v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@aaf140org.highwire.dtl.DTLVardef@c4c0e4org.highwire.dtl.DTLVardef@153de0eorg.highwire.dtl.DTLVardef@117a135_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2024

The modified activity of prolyl 4 hydroxylases (P4Hs) reveals the effect of arabinogalactan proteins (AGPs) on changes in the cell wall during the tomato ripening process

Arabinogalactan proteins (AGPs) are proteoglycans with an unusual molecular structure characterised by the presence of a protein part and carbohydrate chains. Their specific properties at different stages of the fruit ripening programme make AGPs unique markers of this process. An important function of AGPs is to co-form an amorphous extracellular matrix in the cell wall-plasma membrane continuum; thus, changes in the structure of these molecules can determine the presence and distribution of other components. The aim of the current work was to characterise the molecular structure and localisation of AGPs during the fruit ripening process in transgenic lines with silencing and overexpression of SlP4H3 genes. The objective was accomplished through comprehensive and comparative in situ and ex situ analyses of AGPs from the fruit of transgenic lines and wild-type plants at specific stages of ripening. The experiment showed that changes in P4H3 activity affected the content of AGPs and the progress in their modifications in the ongoing ripening process. The analysis of the transgenic lines confirmed the presence of AGPs with high molecular weights (120-60 kDa) at all the examined stages, but a changed pattern of the molecular features of AGPs was found in the last ripening stages, compared to WT. In addition to the AGP molecular changes, morphological modifications of fruit tissue and alterations in the spatio-temporal pattern of AGP distribution at the subcellular level were detected in the transgenic lines with the progression of the ripening process. The work highlights the irreversible impact of AGPs and their alterations on the fruit cell wall assembly and changes in AGPs associated with the progression of the ripening process. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=96 SRC="FIGDIR/small/576594v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@4291e4org.highwire.dtl.DTLVardef@780fdeorg.highwire.dtl.DTLVardef@59c14borg.highwire.dtl.DTLVardef@a12735_HPS_FORMAT_FIGEXP M_FIG C_FIG

plant biology↗