My notes on Plant Biology Europe 2023 at Marseille (day 4)

 06072023

How to conquer a plant using just eight genes: learning from geminiviruses. Rosa Lozano-Duran

Geminiviruses (n>=9 coding genes, splicing enabled) have a very high mutation rate despite being replicated by the host plant system, probably because they force the use of their own polymerase subunit. The most divergent protein in these viruses is C4; it also has several transit peptides, including a sp signal, and it is sufficient and required to elicit infection symptoms [including drought tolerance]. C4 interacts with RLD proteins. Their experiments found that symptoms and viral performance can be uncoupled with the right mutations.

Evolution of cooperation in post-green revolution durum wheat cultivars– Michel COLOMBO

Have we bred weaker competitors after the green revolution? Plots with both low and high density of two genotypes. He confirms this idea and then asks whether we need to continue this trend with current conditions in Montpellier.

Chromatin regulation of and by gene islands in plants– Louis-Valentin METEIGNIER

His work is about the expression of biosynthetic pathways (benzoxazinoids, known to inhibit histone deacetylases) that he suspects have an effect on the performance of intercropping. He mentions recent papers on this hot topic (https://doi.org/10.1073/pnas.2201886120). He intercrops rice and maize, co-planted for 3 weeks (https://dx.doi.org/10.1073/pnas.2001290119).

Identification of genes and metabolites controlling plant-plant interaction (Allelopathy)– Sophie JASINKSI

Adequate varieties should be used to avoid allelopathy affecting performance [often hard to tell from simple competition]. She is carrying out GWAS and Metabolite-WAS [root exudates] analyses in this topic with A. thaliana. She has access to the phenoscope to test a variety of donor (n=385) and receptor (Col-0) accessions. She can observe phenotypic variation. Suspect compounds include glusinolates [aliphatic vs indolic], coumarin, so she looked at candidate genes in these pathways.

Molecular bases of plant-plant interactions: identification of the molecular pathways depending on ESC-1, a RLK involved in the competitive response in Arabidopsis thaliana– Marie INVERNIZZI

91 accessions, 3 species (Poa annua, ) from a French population that compete with A. thaliana.She finds that ESC-1 [naturally variable] plays a role in this competition [some experiments still running], which changes according to stress responses according to transcriptomic data. Arabidopsis senses the competition likely through root exudates.