Biology subjects

Genty, B.

Publications and source records attributed to Genty, B..

3 recordsLinked to original sources

bioRxiv2026

Genetic coupling of hydathode formation with leaf morphogenesis maintains water homeostasis

Hydathodes are specialized leaf structures present across vascular plants that allow guttation by connecting the xylem to the external environment through epithem tissue and permanently open water pores. However, the genetic mechanisms controlling their formation and physiological roles remain poorly understood. Here, we identify a genetic regulatory network that controls hydathode formation and links this process to leaf morphogenesis. This network converges on auxin signaling to coordinate the formation of the three hydathode cell types. We further show that epithem development requires sustained cell proliferation with limited endoreduplication. Analysis of hydathode mutants demonstrates that hydathode size and number are required to prevent reversible leaf flooding. Together, these findings establish a genetic framework for hydathode morphogenesis and uncover a central role for hydathodes in maintaining leaf water homeostasis under fluctuating environmental conditions.

plant biology↗

bioRxiv2023

The genetic basis of dynamic non-photochemical quenching and photosystem II efficiency in fluctuating light reveals novel molecular targets for maize (Zea mays) improvement

Maize (Zea mays L.) is a major global crop species which uses C4 photosynthesis. Although C4 is typically considered to be more efficient than C3 photosynthesis, especially under warmer and drier conditions, there is substantial evidence that its efficiency can still be further improved, which may benefit crop performance. Improving photosynthetic efficiency via targeted manipulation of non-photochemical quenching has focused on a limited set of genes that are known to be important determinants of the NPQ response in C3 plants. The C4 pathway may alter NPQ responses but only relatively few studies have explored genetic variation in NPQ kinetics in species that perform C4 photosynthesis. In addition, studies of NPQ responses in field-grown plants of either C3 or C4 species are especially limited. Here we apply high-definition phenotyping of NPQ responses and photosynthetic efficiency and quantitative trait locus (QTL) mapping using a field-grown maize Multi-parent Advanced Generation Inter-Cross (MAGIC) population, which combines the allelic diversity of eight contrasting inbred lines. We find substantial and consistent variation for dynamic NPQ and PSII efficiency for two subsequent field seasons. Further exploration of candidate genes within three major QTL regions identified a strong impact of allelic variation in expression of the minor PSII antenna protein CP24 (LHCB6) on a major QTL for NPQ and efficiency of PSII photochemistry on chromosome 10.

plant biology↗

bioRxiv2020

ACCLIMATION OF PHOTOSYNTHESIS TO THE ENVIRONMENT 1 regulates Photosystem II Supercomplex dynamics in response to light in Chlamydomonas reinhardtii

Photosynthetic organisms require acclimation mechanisms to regulate photosynthesis in response to light conditions. Here, two mutant alleles of ACCLIMATION OF PHOTOSYNTHESIS TO THE ENVIRONMENT 1 (ape1) have been characterized in Chlamydomonas reinhardtii. The ape1 mutants are photosensitive and show PSII photoinhibition during high light acclimation or under high light stress. The ape1 mutants retain more PSII super-complexes and have changes to thylakoid stacking relative to control strains during photosynthetic growth at different light intensities. The APE1 protein is found in all oxygenic phototrophs and encodes a 25 kDa thylakoid protein that interacts with the Photosystem II core complex as monomers, dimers and supercomplexes. We propose a model where APE1 bound to PSII supercomplexes releases core complexes and promotes PSII heterogeneity influencing the stacking of Chlamydomonas thylakoids. APE1 is a regulator in light acclimation and its function is to reduce over-excitation of PSII centres and avoid PSII photoinhibition to increase the resilience of photosynthesis to high light.

plant biology↗