Biology subjects

Montes, E.

Publications and source records attributed to Montes, E..

4 recordsLinked to original sources

bioRxiv2026

In planta haploid induction in maize and tomato through disruption of KOKOPELLI

Haploid induction is a key component of doubled haploid technology and an increasingly valuable tool for plant breeding, genome editing, and clonal seed production. While in planta haploid induction through haploid inducer lines offers significant advantages over in vitro approaches, its application remains limited in many crop species. Previously, disruption of the sperm cell-expressed KOKOPELLI (KPL) gene was shown to induce maternal haploids in Arabidopsis thaliana. Here, we report the creation of novel haploid inducer lines in two globally important crops, maize (Zea mays), a major staple food crop, and tomato (Solanum lycopersicum), a widely cultivated vegetable crop. Using targeted genome editing, we generated mutations in KPL orthologs and demonstrated that loss of KPL function confers haploid induction capacity, enabling the production of haploid seedlings in both species. These findings establish KPL as a conserved target to trigger haploid induction and expand the genetic toolbox available for haploid inducer development in crop species.

Plant Biology↗

bioRxiv2026

ZmSWEET Sucrose transporters expressed in the endosperm adjacent to the maize embryo are necessary for carbon partitioning and embryo growth

In cereals such as maize, the kernel accumulates large quantities of storage compounds, including carbohydrates, lipids, and proteins, a process that requires tight regulation of nutrient transport. Seeds are composed of distinct tissues: the embryo, the endosperm, and maternal tissues that are symplastically isolated (not connected through plasmodesmata), necessitating specialized nutrient transfer mechanisms. In maize, nutrient transfer from maternal tissues to the endosperm via specialized basal endosperm transfer layer (BETL) cells is well characterized. However, nutrient transfer at the endosperm/embryo interface remains poorly understood. Consequently, the routes by which maternal carbon-derived sugars support embryo growth are still unclear. Our previous transcriptomic profiling uncovered a novel Endosperm domain Adjacent to the embryo Scutellum (EAS) with strong enrichment for transporter genes. Notably, genes encoding three sugar transporters from the SWEET (Sugars Will Eventually be Exported Transporters) family are highly and preferentially expressed in the EAS, suggesting the existence of a specialized sugar transfer mechanism at this interface. We show that the ZmSWEET proteins encoded by these genes are membrane-localized sucrose transporters and are functionally important for kernel development. A gene-edited triple zmsweet14a/14b/15a knock-out mutant exhibits reduced kernel weight and embryo size, significantly decreased embryo oil accumulation at maturity, and altered carbon partitioning within the kernel. In addition to these defects, mutant kernels display a significant reduction in primary root length during germination, indicating either lasting physiological consequences of disrupted sucrose transport during seed development or an additional role for these SWEET transporters during germination. Together, our findings demonstrate that sucrose transport at the endosperm/embryo interface is critical for proper carbon allocation, embryo development, and seed vigor, and identify the EAS as a key functional domain and potential target for improving seed composition.

plant biology↗

bioRxiv2025

Real-time invasion dynamics reveal the drivers of predator spread and prey extirpation on an island

Non-native predators profoundly restructure island biological communities worldwide, yet their management is hindered by limited empirical understanding of the dynamics of predator spread and prey extirpation. Here, we integrate two decades of field surveys, citizen-science records, and standardized transects to reconstruct the invasion of the snake Hemorrhois hippocrepis on Ibiza and its impact on the endangered, endemic lizard Podarcis pityusensis. We found a marked acceleration in range expansion despite intensified culling, evidence for the transition from establishment to spread stages of this invasion. Spatially explicit invasion maps combined with citizen reports of lizard disappearance show a non-linear acceleration in the interval from predator arrival to local prey extirpation, shortening from over ten years in early-invaded areas to three years in recently invaded areas. The observed patterns are consistent with density-dependent predator pressure, which generates a wave-like, rapidly advancing invasion front evidenced by declining snake body condition and reduced efficiency of snake captures in long-invaded areas. Our study empirically confirms theoretical predictions of nonlinear spread and impact dynamics and highlights how citizen science can crucially help documenting early invasion stages. Effectively incorporating the non-linear dynamics of invasions into conservation strategies is urgent to mitigate invasion-driven transformations of fragile island ecosystems worldwide.

ecology↗

bioRxiv2025

Seagrass Extent Expansion in the Gulf of Mexico and Northwestern Caribbean (1987-2021)

Historically, the areal extent of seagrass beds in the Gulf of Mexico, Florida peninsula, and Northwestern Caribbean (Mexico and Cuba) have been estimated to cover approximately 35,510 km2. However, the absence of regular monitoring limits our ability to detect interannual variability and up-to-date health conditions, and to respond to stressors, such as degraded water quality. Seagrass areal extent is one of the core Essential Ocean variables (EOV) of the Global Ocean Observing System (GOOS). Resource managers and researchers are interested in how this seagrass extent and the distribution of this habitat changes over time to focus possible action to mitigate impacts of various stressors, such as degraded water quality. In this study, we mapped 19,405 km2 of seagrasses for the region for the period 2019-2021, using satellite imagery from Landsat 5, Landsat 7, Landsat 8, and Sentinel-2. Interannual changes in seagrass areal extent at 17 representative sites indicated that seagrass habitats increased by 12.3% between 1987 and 2021. Sites off the West Florida coast showed the highest increasing rates in seagrass extent (up to 3.1% yr-1) and lowest rate (-0.43% yr-1) was observed in Biscayne Bay, South Florida. Seagrasses in the Mexican Caribbean showed positive extent expansion rates (1.3-1.8% yr-1), while in Texas were stable over the period of study. Continuous observations of seagrasses like these help managers to understand spatial and temporal patterns of change and encourage further studies on seagrass ecology and carbon stocks.

ecology↗