New Phytologist最新文献

The formation of inflorescences and flowers is essential for the successful reproduction of angiosperms. In the past few decades, genetic studies have identified the LEAFY transcription factor and the UNUSUAL FLORAL ORGANS (UFO) F-box protein as two major regulators of flower development in a broad range of angiosperm species. Recent research has revealed that UFO acts as a transcriptional cofactor, redirecting the LEAFY floral regulator to novel cis-elements. In this review, we summarize the various roles of UFO across species, analyze past results in light of new discoveries and highlight the key questions that remain to be solved.

Rhodophyta (or red algae) are a diverse and species-rich group that forms one of three major lineages in the Archaeplastida, a eukaryotic supergroup whose plastids arose from a single primary endosymbiosis. Red algae are united by several features, such as relatively small intron-poor genomes and a lack of cytoskeletal structures associated with motility like flagella and centrioles, as well as a highly efficient photosynthetic capacity. Multicellular red algae (or macroalgae) are one of the earliest diverging eukaryotic lineages to have evolved complex multicellularity, yet despite their ecological, evolutionary, and commercial importance, they have remained a largely understudied group of organisms. Considering the increasing availability of red algal genome sequences, we present a broad overview of fundamental aspects of red macroalgal biology and posit on how this is expected to accelerate research in many domains of red algal biology in the coming years.

Informed by vegetation maps across high-latitude landscapes, terrestrial biosphere models are a tool that can be used to predict changes in the composition and function of vegetation, above- and belowground, across the land surface in response to changing environmental conditions. However, terrestrial biosphere models represent vegetation characteristics at a finer grain than mapped vegetation communities. These models group plant species that colonize high-latitude biomes by their functional trait variation into plant functional types (PFTs) that characterize the impacts of plant species on, and their response to changes in, their surrounding abiotic and biotic environment. Blume-Werry et al. (2023) found that vegetation mapping units that broadly incorporate multiple plant species and functional types are too coarse, or encompass too much biological variation, to fully capture belowground plant trait variation. However, they did find that they could successfully cluster rooting depth observations into ‘Root Profile Types’, suggesting that modeling PFTs may be a useful tool to characterize above- and belowground linkages across high-latitude environments.

In many arctic and boreal ecosystems, plant roots are constrained by permafrost to a shallow ‘active layer’ of soil that thaws progressively over the course of each growing season. Blume-Werry et al. (2023) identified active layer thickness and the closely related minimum temperature of the coldest month as two of three main abiotic drivers constraining rooting depth distribution in their analysis (a third, cation exchange capacity, is more indicative of nutrient availability than a physical impediment). Furthermore, waterlogging can limit root distribution to surface, oxic soils, and can lead to a thick layer of poorly decomposed, organic peat at the soil surface with different characteristics from mineral soils (Fig. 1; Walker et al., 2003). Indeed, Blume-Werry et al. (2023) found that despite similarities in species composition between wetland and graminoid tundra in CAVM mapping units, rooting depth in wetland tundra was shallower than graminoid tundra. This may indicate that waterlogged conditions can constrain rooting depth distribution, even in vegetation communities dominated by species with aerenchymatous roots. Ranging from rootless mosses and plant-like lichens to vascular graminoids and shrubs, and deciduous and evergreen trees, PFTs inhabiting the arctic tundra and boreal forest vary in their rooting depth distributions, their interactions with soil microbiota, and their ratio of belowground to aboveground tissues (e.g. root : shoot ratio; Chapin et al., 1996). However, terrestrial biosphere models have often neglected the unique characteristics of the species that colonize high-latitude biomes, especially belowground (Iversen et al., 2015, 2018