Leaf senescence is a central, well-coordinated process in the life of plants and comprises the first stage of leaf litter decomposition that ultimately recycles carbon and nutrients. Microorganisms are known to participate in leaf litter decomposition, but little is known on the role of microbiota in leaf senescence and the initiation of decay immediately following tissue death. In this work, we aim to study the involvement of leaf microbiota in senescence and early breakdown of cell components in leaves by combining microbial, chemical and ecological approaches, using microscopic and chemical tools at various scales. We will study sorghum (Sorghum bicolor) – a staple food for millions of people and fodder for farm animals across the world. Importantly, the selection of grass as a model plant will allow us analyzing mature, senescing, dead and decomposing tissue along a developmental axis on the same leaf and under identical conditions. Specifically, we will correlate microscale mapping of leaf topography, chemical composition and water content, with the microscale microbial organization on the leaf and with isotopic composition of CO2 emission, over time and across space along the axis of the senescing and decaying sorghum leaf. This study has the potential to reveal novel interactions between microbiota, plant developmental processes, and ecologically significant mechanisms. It will shed light on the dynamics of bacterial organization and may reveal new roles that plant microbiota plays in leaf senescence and early decay, which are key processes in the carbon and nutrient cycles in natural and agricultural systems.

Collaboration:

Rivka Elbaum, Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel
Nadav Kashtan, Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel