Abstract
Global warming is expected to have negative effects on agricultural productivity and thus on the food supply chain in the coming decades. The constant increase in average temperatures predicted for the near future will have a strong impact in some ecologically vulnerable areas of the planet, inducing a strong stress on plant species and critically impacting on their sexual reproduction. This phenomenon determines morphological, physiological, and molecular alterations in reproductive organs which negatively affect crop performance and yield, with heavy economic consequences. In Angiosperms, which are the main source of edible vegetables, seeds, and fruits, the male component of the flower is the most affected by heat stress (HS), often resulting in male sterility. While different studies have investigated these aspects, HEATSTOP proposes a novel approach to the issue, focusing on the molecular mechanisms underlying pollen-pistil interactions and investigating how they are affected by high daily temperatures during pollen development and release. For this purpose, HS-sensitive and HS-tolerant cultivars of rapeseed (Brassica napus L.), will be exposed to high temperature regimes in crucial steps of the microsporogenesis. The HS response will be monitored measuring photosynthetic efficiency in stressed and control groups during the experiment, and the impact of HS on fertility will be assessed by comparing fruit and seed parameters for the two groups at the end of the experiment. HS effects on pollen development will instead be assessed using a combination of imaging and molecular techniques, comparing pollen productivity, dimensions, viability, and germinability between stressed and control plants. Eventually, the impact of HS on male-female crosstalk will be achieved through an integrated cytological, molecular, and genetic approach, enhancing the changes in lipids, proteins, and miRNAs in pollen during germination, with a special focus on pollen-secreted molecules and nanovesicles. The latter, called pollensomes, have been recently discovered and their role in pollen germination and plant fertilization is still unknown. The present study will not only characterize the content of the pollensomes for the selected species in terms of proteins and lipids, but it will also determine for the first time the miRNAs carried by these vesicles, also detecting possible HS-induced changes in pollensomes composition. In summary, HEATSTOP will provide specific insight into the pathways involved in the plant response to HS during reproduction, and specifically on the molecular basis of HS-induced male sterility, on economically valuable crops. A comprehensive understanding of these mechanisms will unravel the physiological, molecular, and genetic basis of the consequent yield loss, paving the way for biotechnological applications aimed at breeding HS-tolerant varieties and improving crop productivity.
Project details
Unibo Team Leader: Stefano Del Duca
Unibo involved Department/s:
Dipartimento di Scienze Biologiche, Geologiche e Ambientali
Coordinator:
ALMA MATER STUDIORUM - Università di Bologna(Italy)
Total Eu Contribution: Euro (EUR) 230.127,00
Total Unibo Contribution: Euro (EUR) 114.890,00
Project Duration in months: 24
Start Date:
30/11/2023
End Date:
28/02/2026
