Biology subjects

Manzanares, C.

Publications and source records attributed to Manzanares, C..

4 recordsLinked to original sources

bioRxiv2026

Combing agronomic biofortification with a Zn-efficient wheat line synergistically increases grain Zn concentrations with varied effects on Cd in wheat grains

(Background and aims) Wheat grains are often too low in zinc (Zn) compared to human dietary needs, and are a major dietary source of highly toxic cadmium (Cd). Biofortification strategies can increase Zn in edible grain, but must not increase grain Cd. (Methods) We investigated the individual and combined effects of genetic and agronomic biofortification on Zn and Cd in wheat grains. Non-transgenic Bobwhite (BW-NT) and an OsNAS2-expressing line (BW-NAS) were grown in a pot experiment with isotope-labeled mineral Zn (70Zn) and green manure (70Zn, 106Cd). At flowering and maturity, Zn and Cd were quantified in wheat biomass. Wheat contents of Zn and Cd derived from inputs versus soil were determined using stable isotope analyses. (Results) Individually, the OsNAS2-expressing wheat and input application increased grain Zn. Combined OsNAS2 expression and input application led to grain concentrations of 76{+/-}4 mg kg-1 with mineral Zn application and 61{+/-}7 mg kg-1 with green manure. This was 154-217% higher than the 24{+/-}1 mg kg-1 observed in the BW-NT control and significantly higher than the additive effects of each strategy individually. The OsNAS2-expressing line increased grain Cd to 0.214{+/-}0.002 mg kg-1 under green manure, compared to 0.12{+/-}0.01 mg kg-1 in the BW-NT control. No other treatment increased grain Cd. (Conclusions) Our results encourage development of integrated genetic and agronomic biofortification strategies to increase grain Zn. They also underscore the need for careful monitoring of grain Cd concentrations when organic amendments are paired with genetic biofortification strategies.

plant biology↗

bioRxiv2026

Evolutionary signatures of self-incompatibility genes in grasses: high diversity, trans-generic polymorphism and co-evolution

In many flowering plants, self-incompatibility (SI) is a genetically controlled recognition system that prevents self-fertilization, thereby promoting outcrossing and maintaining genetic diversity within populations. The gametophytic SI system in grasses (Poaceae) is governed by two multiallelic loci, S and Z, each locus comprising of three genes governing the initial recognition between pollen and stigma. Identifying these genes establishes the molecular basis of SI in grasses, but how its unique two-locus architecture has shaped the evolution of the underlying loci and recognition genes remains largely unexplored. Here, we report targeted sequence capture of SI genes in 362 genotypes across nine forage grass species, revealing extensive allelic richness and sequence diversity. The SI genes exhibited elevated nucleotide diversity ({pi}) (0.134 < {pi} < 0.403) and great amino acid sequence divergence, ranging between 48.2-58.0% for the female determinants (sS and sZ) and 66.5-83.4% for the male determinants (SI-DUF247). The SI-DUF247 proteins also displayed trans-generic polymorphism, indicating that alleles predate speciation. Phylogenetic analysis of SI determinants showed congruence at both S- and Z-locus, consistent with co-evolution of recognition partners. Our results demonstrate that the unique two-locus SI system in grasses shares evolutionary characteristics with other SI systems, suggesting that their reproductive function is shaping their evolution. These findings also indicate that the grass SI loci are under long-term balancing selection to maintain recognition specificity while creating sufficient allelic diversity. Our study provides comprehensive sequence resources for SI genes and new insights into the evolution of the unique two-locus SI system of grasses.

plant biology↗

bioRxiv2022

Fine-mapping and comparative genomic analysis reveal the gene composition at the S and Z self-incompatibility loci in grasses

Self-incompatibility (SI) is a genetic mechanism of hermaphroditic plants to prevent inbreeding after self-pollination. Allogamous Poaceae species exhibit a unique gametophytic SI system controlled by two multi-allelic and independent loci, S and Z. Despite intense research efforts in the last decades, the genes that determine the initial recognition mechanism are yet to be identified. Here, we report the fine-mapping of the Z-locus in perennial ryegrass (Lolium perenne L.) and provide evidence that the pollen and stigma components are determined by two genes encoding DUF247 domain proteins (ZDUF247-I and ZDUF247-II) and the gene sZ, respectively. The pollen and stigma determinants are located side-by-side and were genetically linked in 10,245 individuals of two independent mapping populations segregating for Z. Moreover, they exhibited high allelic diversity as well as tissue-specific gene expression, matching expected characteristics of SI determinants known from other systems. Revisiting the S-locus using the latest high-quality whole-genome assemblies revealed a similar gene composition and structure as found for Z, supporting the hypothesis of a duplicated origin of the two-locus SI system of grasses. Ultimately, comparative genomic analyses across a wide range of self-compatible and self-incompatible Poaceae species revealed that the absence of a functional copy of at least one of the six putative SI determinants is accompanied by a self-compatible phenotype. Our study provides new insights into the origin and evolution of the unique gametophytic SI system in one of the largest and economically most important plant families.

plant biology↗

bioRxiv2021

Identification of candidate genes for self-compatibility in perennial ryegrass (Lolium perenne L.)

Self-incompatibility (SI) is a genetic mechanism preventing self-pollination in approximately 40% of plant species. Two multiallelic loci, called S and Z, control the gametophytic SI system of the grass family (Poaceae), which contains all major forage grasses. Loci independent from S and Z have been reported to disrupt SI and lead to self-compatibility (SC). A locus causing SC in perennial ryegrass (Lolium perenne L.) was previously mapped on linkage group (LG) 5 in a F2 population segregating for SC. Using a subset of the same population (n=68), we first performed low-resolution quantitative trait locus (QTL) mapping to exclude the presence of additional, previously undetected contributors to SC. The previously reported QTL on LG 5 explained 38.4% of the phenotypic variation, and no significant contribution from other genomic regions was found. This was verified by the presence of significantly distorted markers in the region overlapping with the QTL. Second, we fine mapped the QTL to 0.26 cM using additional 2,056 plants and 23 novel sequence-based markers. Using an Italian ryegrass (Lolium multiflorum Lam.) genome assembly as reference, the markers flanking SC were estimated to span a ~3 Mb region encoding for 57 predicted genes. Among these, seven genes were proposed as relevant candidate genes based on their annotation and function described in previous studies. Our work is a step forward to identify SC genes in forage grasses and provides diagnostic markers for marker-assisted introgression of SC into elite germplasm. Key messageA previously reported QTL conferring self-compatibility to perennial ryegrass was fine mapped to a 0.26 cM locus, corresponding to an estimated ~ 3 Mb physical region containing 57 predicted protein-encoding genes.

plant biology↗