PLEASE NOTE: Four publications appear in the list with no IF.
Principal Investigator (PI): Plant J (2017): IF 5.5; PNAS (2015): IF 9.674.
Marti: J Exp Botany (2014): IF 5,7; Envir and Exp Botany (2016): IF 3.7.
With these, SUM OF IFs: PI=84.413; ALL (PI+PARTICIPANTS)=138,086
Total H- index of the group: 80 (PI:42; S.F. 18; V.L. 13; L.M. 7)
Endogenous ligands termed "damage-associated molecular patterns" (DAMPs) are involved in several key processes in both animals and plants, from development, to homeostasis and pathology caused by both endogenous and exogenous sources. DAMPs often trigger complex responses that, besides inflammation and metabolic changes, include tissue maintenance/repair processes. In animals and plants, fragments of two linear and acidic high molecular weight polysaccharides of the extracellular matrix, hyaluronan (HA) in vertebrates and homogalacturonan (HGA) in plants, are specifically perceived as DAMPs. Fragments of 10-16 residues of HA and HGA [the latter indicated as oligogalacturonides (OGs)] show the highest immune-stimulant activity. This project focuses on OGs, with the goal of proving that these molecules are important signals in both development and growth-defence trade-off. We will use a novel approach based on the release of OGs in planta on command by an engineered inducible molecular tool named OG-machine (OGM) that allows a targeted expression of the OGM at the cell/tissue level to dissect the OG function. OGs at high levels trigger a deleterious hyper-immunity, and homeostatic mechanisms that prevent their hyper-accumulation must exist. We aim at demonstrating that inactivation played by newly discovered specific OG oxidases (OGOXs) belonging to the complex berberine-bridge enzyme-like (BBEl) family is one of such mechanisms. Disentangling the role of bioactive oligosaccharides in growth-defence trade-off may lead to novel strategies to obtain plants more resistant to pathogens, yet with normal/better growth performance.
By exploiting unique tools and expertise developed in many years, this project addresses questions that are
among the most challenging in the field. A high risk/high gain goal is to prove that OGs are master regulators of plant development and important signals in the growth-defense trade-off. Disentangling their action may lead to design novel strategies to obtain plants more resistant to pathogens, yet with normal and/or better growth performance. Progress in the field of HGA and OG biology will help translational applications and agricultural advances. The enhancement of natural plant resistance is a promising strategy for controlling plant diseases, which are a major cause of economic losses, decreased yield and toxin contamination of food products. However, the growth-defence trade off may result in decreased growth and yield. In particular, negative effects on root development and performance have a very important impact on crop growth, quality and yield. Therefore, the understanding of the developmental and architecture dynamics in relation to immunity as well as to cell wall structure is central for breeding and biotechnological efforts aimed at enhancing yield and reducing losses caused by microbial pathogens.
Moreover, DAMP homeostasis mechanisms are relevant not only for plant biologists but also for researchers working in the animal field. Oxidation-based mechanisms may contribute to HA homeostasis and be searched using strategy similar to that adopted in our work. This study requires specific know-how in a number of sophisticated technologies and will provide a unique training platform for young scientists to meet the increasing demand for researchers in this area, ensuring multidisciplinary training at the highest level. Overall, this proposal will provide the basic knowledge and expertise that will be relevant to exploit for enhancing response to pathogens in crop plants with little or no effects on growth and yield, and more in general, for plant biotechnology.
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