Biology subjects

Menard, G. N.

Publications and source records attributed to Menard, G. N..

3 recordsLinked to original sources

bioRxiv2025

Associative transcriptomics in Brassica napus suggests a role for Arabidopsis Response Regulator orthologs in seedling vigour

Background and AimsOptimal seedling vigour determines successful crop establishment and its ability to overcome abiotic and biotic threats. Seedling vigour is regulated by several different factors, genetic, physiological, environmental, post-harvest storage, making it challenging to fully elucidate. The aim of this study was to dissect the genetic basis of post-germinative seedling traits and its implications in seedling establishment success in Brassica napus. MethodsA B. napus diversity set panel was used to phenotype seedling establishment traits in the soil including days to emergence, days to appearance of first and second true leaves, and days to reach 25% and 50% cotyledon expansion. An associative transcriptomics analysis was performed to identify the genetic factors regulating seedling establishment. Key ResultsThe study of different phenotypic traits highlighted the relevance of scoring more than one trait to determine good performers. Gene expression markers significantly associated with the studied traits were associated with the cytokinin signalling pathway and photomorphogenesis. Gene expression markers for orthologues of Arabidopsis thaliana RESPONSE REGULATOR 4 and 5 (ARR4, ARR5) were significantly associated with days to appearance of second leaf. SUPPRESSOR OF PHYA-105 1 (SPA1) orthologues were associated with cotyledon area, meanwhile ALTERED SEED GERMINATION 7 (ASG7) and PSEUDO-RESPONSE REGULATOR 7 (PRR7) orthologues were associated with days to emergence, suggesting a complex and interconnected regulatory pathway controlling several traits of seedling establishment. ConclusionsThese results uncovered promising genes that appear to work in a complex and interconnected manner controlling several post-germinative seedling traits affecting final seedling establishment speed.

plant biology↗

bioRxiv2023

Ketocarotenoid production in tomato triggers metabolic reprogramming and cellular adaptation: The quest for homeostasis?

Plants are sessile and therefore have developed an extraordinary capacity to adapt to external signals. Here, the focus is on the plasticity of the plant cell to respond to new intracellular cues. Ketocarotenoids are high-value natural red pigments with potent antioxidant activity. In the present study, system level analyses have revealed that the heterologous biosynthesis of ketocarotenoids in tomato initiated a series of cellular and metabolic mechanisms to cope with the formation of metabolites that are non-endogenous to the plant. The broad multilevel changes were linked to, among others, (i) the remodelling of the plastidial membrane, where the synthesis and storage of ketocarotenoids occurs, (ii) the recruiting of core metabolic pathways for the generation of metabolite precursors and energy, and (iii) redox control. The role of the metabolites as regulators of cellular processes shown here, reinforces their pivotal role suggested in the remodelled "central dogma" concept.

systems biology↗

bioRxiv2022

Oil accumulation in leaves driven by a native promoter-gene fusion created using CRISPR/Cas9 mediated genomic deletion

Achieving gain-of-function phenotypes without inserting foreign DNA is an important challenge for plant biotechnologists. Here we show that a gene can be brought under the control of a promoter from an upstream gene by deleting the intervening genomic sequence using dual-guide CRISPR/Cas9. We fuse the promoter of a non-essential photosynthesis-related gene to DIACYLGLYCEROL ACYLTRANSFERASE 2 (DGAT2) to drive oil biosynthesis in leaves of a lipase deficient sugar-dependent 1 mutant. DGAT2 expression is enhanced more than twenty-fold and the triacylglycerol content increases by around thirty-fold. This strategy offers a transgene-free route to engineering gain-of-function traits such as high lipid forage to increase the productivity and sustainability of ruminant farming.

bioengineering↗