Biology subjects

Diogo, R.

Publications and source records attributed to Diogo, R..

3 recordsLinked to original sources

bioRxiv2026

Single-Cell Omics to Uncover Cell-Type-Specific Gene Regulatory Networks Driving Mucilage Production in Specialized Roots

Aerial roots of certain maize (Zea mays) and sorghum (Sorghum bicolor) genotypes secrete a carbohydrate-rich mucilage that sustains nitrogen-fixing bacteria, and the underground roots of most plants secrete mucilage at their tips. In both settings, border cells released from the root cap produce this mucilage, yet the genes controlling their formation remain largely unknown. We sequenced the RNA of about 23,000 nuclei from mucilage-secreting roots of maize, sorghum, and Medicago truncatula, sampled before and after secretion. Each species yielded 10 to 15 clusters, which we annotated with published markers and with new markers that we validated by in situ hybridization in the two cereals and by promoter-reporter fusions in M. truncatula. We then inferred modular and cell type-specific gene regulatory networks. Transcriptional programs diverged across the three species except in the quiescent center and the meristem, and in the clusters containing border cells, where a shared set of regulators emerged. Silencing three of five candidate regulators reduced border cell number, while silencing a partially overlapping set of three regulators reduced root diameter in M. truncatula. Silencing the C2H2 zinc finger protein MtrunA17_Chr1g0148421 also reduced border cell viability. A maize insertion mutant of bzip89 released fewer border cells than the wild type. These networks offer entry points for tuning mucilage production in cereal and legume crops.

plant biology↗

bioRxiv2025

Genetic determinants of aerial root traits that support biological nitrogen fixation in maize

Modern agriculture depends on chemically synthesized nitrogen fertilizer, which ensures high yields but also can carry significant environmental and economic costs. Biological nitrogen fixation (BNF) already supplies nitrogen to legume crops and several avenues of research are underway to extend it to non-legume crops. In maize (Zea mays), aerial roots have been shown to contribute to BNF in some varieties, and both having many aerial roots and large aerial roots contributes to the fixation trait. However, much of the genetics controlling aerial root number and size is still unknown. Here we validate and quantify BNF in maize varieties from Southern Mexico under controlled conditions and evaluate a population of double haploids derived from the elite inbred PHZ51 crossed with these varieties. We find that most aerial root traits (root number, nodes with roots, root size) are reasonably heritable (h2 0.5-0.75) and generally uncorrelated with each other. QTL mapping identifies 5 QTL each affecting nodes with aerial roots and aerial root number per node; in both cases all but 1 QTL show an increase from the landrace allele. We also identify 11 QTL for aerial root diameter, with most positive QTL coming from PHZ51. Between the two populations, only a few QTL overlap, indicating a presumably high diversity of genes affecting aerial root morphology in landrace populations. Combining the best QTL into elite material may provide a path toward meaningful levels of BNF for maize, and additional work is needed to determine how viable this approach will be in field settings.

plant biology↗

bioRxiv2018

Evolutionary parallelisms of pectoral and pelvic network-anatomy from fins to limbs

Pectoral and pelvic lobe-fins transformed into fore- and hindlimbs during the Devonian period, enabling the water-to-land transition in tetrapods. In the timespan of ~60 million years, transitional forms evolved, spanning a wide range of morphologies. Here we traced the evolution of well-articulated appendicular skeletons across the fins-to-limbs transition, using a network-based approach and phylogenetic tools to quantify and compare topological features of skeletal anatomy of fins and limbs. We show that the topological arrangement of bones in the pectoral and pelvic appendages evolved in parallel during the fins-to-limbs transition, occupying overlapping regions of the morphospace, following a directional mode of evolution, and decreasing their disparity over time. We identify the presence of digits as the morphological novelty triggering significant topological changes that clearly discriminated limbs from fins. The origin of digits caused an evolutionary shift towards appendages that were less densely and heterogeneously connected, but more assortative and modular. Topological disparity likewise decreased for both appendages: for the pectoral appendage, until the origin of amniotes; for the pelvic appendage, until a time concomitant with the earliest-known tetrapod tracks. Finally, we tested and rejected the presence of a pectoral-pelvic similarity bottleneck for the network-anatomy of appendages at the origin of tetrapods. We interpret our findings in the context of a dynamic compromise between possibly different functional demands in pectoral and pelvic appendages during the water-to-land transition and a shared developmental program constraining the evolvability of limbs.

evolutionary biology↗