Plant extinction excels plant speciation in the Anthropocene

Molecular aspects of heat stress sensing in land plants

Heat stress impacts all aspects of life, from evolution to global food security. Therefore, it becomes essential to understand how plants respond to heat stress, especially in the context of climate change. The heat stress response (HSR) involves three main components: sensing, signal transduction, and cellular reprogramming. Here, I focus on the heat stress sensing component. How can cells detect heat stress if it is not a signalling particle? To answer this question, I have looked at the molecular definition of heat stress. It can be defined as any particular rise in the optimum growth temperature that leads to higher-than-normal levels of reactive molecular species and macromolecular damage to biological membranes, proteins, and nucleic acid polymers (DNA and RNA). It is precisely these stress-specific alterations that are detected by heat stress sensors, upon which they would immediately trigger the appropriate level of the HSR. In addition, the work towards thermotolerance is complemented by a second type of response, here called the cellular homeostasis response (CHR). Upon mild and extreme temperature changes, the CHR is triggered by plant thermosensors, which are responsible for monitoring temperature information. Heat stress sensors and thermosensors are distinct types of molecules, each with unique modes of activation and functions. While many recent reviews provide a comprehensive overview of plant thermosensors, there remains a notable gap in the review literature regarding an in-depth analysis of plant heat stress sensors. Here, I attempt to summarise our current knowledge of the cellular sensors involved in triggering the plant HSR.

Fossil or Non-Fossil: A Case Study in the Archaeological Wheat Triticum parvicoccum (Poaceae: Triticeae)

BACKGROUND/OBJECTIVES

The archaeobotanical taxon "Triticum parvicoccum" was first described in 1980 as a small-grained, naked, free-threshing, and dense ear tetraploid wheat species (2n = 4x = 28) identified from archaeological remains. This primitive tetraploid, cultivated in the Levant approximately 9000 years ago and subsequently dispersed throughout the Fertile Crescent, represents a potential contributor of the BBAA genomes to T. aestivum. This study aims to resolve the complex nomenclatural status of this taxon, which has remained ambiguous due to competing interpretations under fossil and non-fossil taxonomic regulations.

METHODS

We conducted a comprehensive nomenclatural review to evaluate the taxonomic validity of T. parvicoccum, analyzing previous research on the classification of archaeobotanical materials in relation to fossil status.

RESULTS

Our analysis demonstrated that archaeobotanical materials do not qualify as fossils and led to the validation of the taxon at a subspecific rank as a non-fossil entity: T. turgidum subsp. parvicoccum Kislev. subsp. nov. The holotype was established using a charred rachis fragment from Timnah (Tel Batash), an archaeological site on the inner Coastal Plain (Shfela) adjacent to the western piedmont of the Judean Mountains, Israel.

CONCLUSIONS

This study resolves the longstanding nomenclatural uncertainty surrounding this archaeologically significant wheat taxon, providing a valid taxonomic designation that reflects its biological and historical importance while adhering to current botanical nomenclature standards.

A conceptual framework to inform conservation status assessments of non-charismatic species

The conservation of at-risk species is rooted in the ability of natural resource agencies to recognize when a species is imperiled and in need of regulatory action, which can be a difficult task due to incomplete information. Freshwater mussels (Bivalvia: Unionidae), are a highly imperiled group of aquatic organisms and conservation tools such as the NatureServe Conservation Methodology provide a framework to determine whether a species is in decline and in need of potential management. For data deficient species like mussels this method relies heavily on expert opinion, which can lead to biased estimates of conservation status that may not reflect the true nature of their conservation need. To address these concerns, we developed a standardized and repeatable conservation ranking framework that builds upon the established NatureServe methodology. We compiled a data set of 12,018 species occurrence records of 48 freshwater mussel species, 17 geospatial layers representing environmental threats, and life history information to estimate their response to those threats. Estimated ranks were compared to previous status ranking metrics from IUCN, NatureServe, USFWS and Texas Parks and Wildlife Department. Of the 48 species we evaluated, three were classified as critically imperiled, 16 were imperiled, 15 were vulnerable, 13 were apparently secure, and one was secure. We found 48% of species assessed were less imperiled than NatureServe estimates and found 10% of species assessed to have a higher conservation status than previous evaluations. Our approach can be applied to other species in other regions and should be useful for managers and scientists interested in reducing uncertainty and improving reproducibility in assignment of conservation ranks, particularly for those with limited information.

Population genomics and distribution modeling revealed the history and suggested a possible future of the endemic Agave aurea (Asparagaceae) complex in the Baja California Peninsula

Agaves are an outstanding arid-adapted group of species that provide a unique chance to study the influence of multiple potential factors (i.e., geological and ecological) on plant population structure and diversification in the heterogeneous environment of the Baja California Peninsula. However, relatively little is known about the phylogeography of the endemic agave species of this region. Herein, we used over 10,000 single-nucleotide polymorphisms (SNPs) and spatial data from the Agave aurea species complex (i.e., A. aurea ssp. aurea, A. aurea ssp. promontorii, and A. aurea var. capensis) to resolve genetic relationships within this complex and uncover fine-scale population structure, diversity patterns, and their potential underlying drivers. Analyses resolved low genetic structure within this complex, suggesting that A. aurea is more likely to represent several closely related populations than separate species or varieties/subspecies. We found that geographical and historical ecological characteristics-including precipitation, latitude, and past climatic fluctuations-have played an important role in the spatial distribution of diversity and structure in A. aurea. Finally, species distribution modeling results suggested that climate change will become critical in the extinction risk of A. aurea, with the northernmost population being particularly vulnerable. The low population genetic structure found in A. aurea is consistent with agave's life history, and it is probably related to continuity of distribution, relatively low habitat fragmentation, and dispersion by pollinators. Together, these findings have important implications for management and conservation programs in agave, such as creating and evaluating protected areas and translocating and augmentation of particular populations.

The legacies of the "Father of Hybrid Rice" and the seven representative achievements of Chinese rice research: A pioneering perspective towards sustainable development

The "Father of Hybrid Rice", Yuan Longping, created high-yield hybrid rice that can feed tens of millions of people annually. The research achievements of Yuan and his team on low cadmium-accumulating rice and sea rice, in addition to hybrid rice, as well as those of a large number of Chinese scientists engaged in rice research in other six areas, including the rice genome, purple endosperm rice, de novo domestication of tetraploid rice, perennial rice, rice blast disease, and key genes for high nitrogen use efficiency, play an important role in promoting the realization of the United Nations Sustainable Development Goals 2 and 12. The purpose of this review is not to elaborate on the details of each research, but to innovatively summarize the significance and inspiration of these achievements to ensure global food security and achieve sustainable agriculture. In the future, cultivating new rice varieties through modern biotechnology, such as genome editing, will not only reduce hunger, but potentially reduce human-land conflicts, improve the environment, and mitigate climate change.

Transformations of Vascular Flora of a Medieval Settlement Site: A Case Study of a Fortified Settlement in Giecz (Wielkopolska Region, Western Poland)

Exceptional components of the cultural landscape of Central Europe include archaeological sites, e.g., castle ruins, prehistoric or medieval fortified settlements, other settlements and burial mounds. The plants associated with them help us explain the processes of species persistence on habitat islands as well as the process of naturalization of crop species, which escape from fields or are abandoned. This study describes the flora of a medieval fortified settlement in Giecz (Wielkopolska region, western Poland), presents plant indicators of former settlements (relics of cultivation), species of high conservation value, and transformations of the vascular flora of this settlement over a few decades. Field research was conducted in 1993–1994, 1998–1999, and 2019. At the study site, 298 species of vascular plant species were recorded, and nearly 70% of them (201 species) have persisted there over the last 20 years. The flora includes seven relics of cultivation (Artemisia absinthium, Leonurus cardiaca, Lycium barbarum, Malva alcea, Pastinaca sativa, Saponaria officinalis, and Viola odorata), 5 species threatened with extinction in Poland and/or Wielkopolska, and 53 species of least concern (LC) according to the European red list. We have attempted to explain the floristic changes. The archaeological site in Giecz is of high conservation value, very distinct from the surrounding cultural landscape because of its specific flora, and composed of species from various habitats (e.g., dry grasslands, wooded patches, meadows, aquatic and ruderal habitats), including threatened, protected, and relic species.

Pervasive genome duplications across the plant tree of life and their links to major evolutionary innovations and transitions

Whole-genome duplication (WGD) has occurred repeatedly during plant evolution and diversification, providing genetic layers for evolving new functions and phenotypes. Advances in long-read sequencing technologies have enabled sequencing and assembly of over 1000 plant genomes spanning nearly 800 species, in which a large set of ancient WGDs has been uncovered. Here, we review the recently reported WGDs that occurred in major plant lineages and key evolutionary positions, and highlight their contributions to morphological innovation and adaptive evolution. Current gaps and challenges in integrating enormous volumes of sequenced plant genomes, accurately inferring WGDs, and developing web-based analysis tools are emphasized. Looking to the future, ambitious genome sequencing projects and global efforts may substantially recapitulate the plant tree of life based on broader sampling of phylogenetic diversity, reveal much of the timetable of ancient WGDs, and address the biological significance of WGDs in plant adaptation and radiation.

Rethinking the Connections between Ecosystem Services, Pollinators, Pollution, and Health: Focus on Air Pollution and Its Impacts

Ecosystems provide many services that are essential for human activities and for our well-being. Many regulation services are interconnected and are fundamental in mitigating and hindering the negative effects of several phenomena such as pollution. Pollution, in particular airborne particulate matter (PM), represents an important risk to human health. This perspective aims at providing a current framework that relates ecosystem services, regulating services, pollination, and human health, with particular regards to pollution and its impacts. A quantitative literature analysis on the topic has been adopted. The health repercussions of problems related to ecosystem services, with a focus on the effects of atmospheric particulate matter, have been highlighted in the work throughout a case study. In polluted environments, pollinators are severely exposed to airborne PM, which adheres to the insect body hairs and can be ingested through contaminated food resources, i.e., pollen and honey. This poses a serious risk for the health of pollinators with consequences on the pollination service and, ultimately, for human health.

Colombia's bioregions as a source of useful plants

The aim of our study was to assess the importance of different Colombian bioregions in terms of the supply of useful plant species and the quality of the available distribution data. We assembled a dataset of georeferenced collection localities of all vascular plants of Colombia available from global and local online databases. We then assembled a list of species, subspecies and varieties of Colombia's useful plants and retrieved all point locality information associated with these taxa. We overlaid both datasets with a map of Colombia's bioregions to retrieve all species and useful species distribution records in each bioregion. To assess the reliability of our estimates of species numbers, we identified information gaps, in geographic and environmental space, by estimating their completeness and coverage. Our results confirmed that Colombia's third largest bioregion, the Andean moist forest followed by the Amazon, Pacific, Llanos and Caribbean moist forests contained the largest numbers of useful plant species. Medicinal use was the most common useful attribute across all bioregions, followed by Materials, Environmental uses, and Human Food. In all bioregions, except for the Andean páramo, the proportion of well-surveyed 10×10 km grid cells (with ≥ 25 observation records of useful plants) was below 50% of the total number of surveyed cells. Poor survey coverage was observed in the three dry bioregions: Caribbean deserts and xeric shrublands, and Llanos and Caribbean dry forests. This suggests that additional primary data is needed. We document knowledge gaps that will hinder the incorporation of useful plants into Colombia's stated plans for a bioeconomy and their sustainable management. In particular, future research should focus on the generation of additional primary data on the distribution of useful plants in the Amazon and Llanos (Orinoquia) regions where both survey completeness and coverage appeared to be less adequate compared with other regions.