Light in the darkness: how ferns flourished in the ancestral angiosperm forest.

This article is a Commentary on Cai et al. (2021), 230: 1201–1213

Regulatory mechanisms controlling stomatal behaviour conserved across 400 million years of land plant evolution

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Anemochore Seeds Harbor Distinct Fungal and Bacterial Abundance, Composition, and Functional Profiles

Many plants adapted to harsh environments have evolved low seed mass (‘light seeds’) with specific dispersal strategies, primarily either by wind (anemochory) or water (hydrochory). However, the role of their seed microbiota in their survival, and their seed microbial abundance and structure, remain insufficiently studied. Herein, we studied the light seed microbiome of eight anemochores and two hydrochores (as controls) collected from four provinces in China, using qPCR and metagenomic sequencing targeting both bacteria and fungi. Substantial variations were found for seed endophytic fungi (9.9 × 1010~7.3 × 102 gene copy numbers per seed) and bacteria (1.7 × 1010~8.0 × 106). Seed microbial diversity and structure were mainly driven by the plant genotype (species), with weak influences from their host plant classification level or dispersal mode. Seed microbial composition differences were clear at the microbial phylum level, with dominant proportions (~75%) for Proteobacteria and Ascomycota. The light seeds studied harbored unique microbial signatures, sharing only two Halomonas amplicon sequence variants (ASVs) and two fungal ASVs affiliated to Alternaria and Cladosporium. A genome-level functional profile analysis revealed that seed bacterial microbiota were enriched in amino acid, nucleoside, and nucleotide biosynthesis, while in fungal communities the generation of precursor metabolites and respiration were more highly represented. Together, these novel insights provide a deeper understanding of highly diversified plant-specific light seed microbiota and ecological strategies for plants in harsh environments

Editorial: Linking Stomatal Development and Physiology: From Stomatal Models to Non-model Species and Crops

Stomata are highly dynamic valves in the epidermis of plants. These microscopic structures regulate the exchange of gases with the atmosphere and are essential for plant survival on land (Raven, 2002). There is an enduring fascination with stomata because of their specialized nature: from their unique development out of undifferentiated epidermal cells; to the environmental and internal signals they respond to; and the impacts their function have on climate and global change. These key themes have been the topic of many classical compendiums and scientific conferences (Jarvis and Mansfield, 1981; Ziegler et al., 1987; Roelfsema and Kollist, 2013). Research in the past two decades has accelerated our understanding of stomatal function, particularly through the accumulation of a critical mass of knowledge on the genetic underpinnings of stomatal development and physiology in the model angiosperm Arabidopsis (Assmann and Jegla, 2016; Qi and Torii, 2018). In this Frontiers eBook, we sought to bring together the latest research and reviews on stomatal biology that span a vast continuum: from cells to ecosystems. The articles were solicited with four key themes in mind: (1) The coordination of stomatal development with plant growth, development, and environmental signaling; (2) The role of stomatal development in plant acclimation and adaptation to the environment; (3) The influence of stomatal development and function on plant resource use, ecosystem processes, and global climate; and (4) The selection for stomatal traits in plant evolution, crop domestication and breeding, and designing food for the future.ISSN:1664-462

Morphoanatomical and phylogenetic characterization of the ectomycorrhiza between Laccaria squarrosa with Pinus pseudostrobus and its relevance for reforestation programs.

Background: Pinus (Coniferophyta) and Laccaria (Basidiomycota) establish ectomycorrhizal symbioses in natural forests. However, their detailed morphoanatomical and phylogenetic characterization have received little attention. Accurate identification of native host symbionts is of paramount relevance to the production of mycorrhized seedlings for successful reforestation programs. Questions/Objective: We aimed to determine if L. squarrosa is able to establish ectomycorrhizal symbiosis with gymnosperms, thereby widening its host range and highlighting its relevance as a potential inoculant for pine seedlings. Currently, L. squarrosa is only known from its type collection associated with the angiosperm Fagus grandifolia var. mexicana. Studied species: The fungus L. squarrosa and Pinus pseudostrobus, a tree endemic to Mexico. Study site and dates: A Pinus-Quercus forest in Piedra Canteada, Nanacamilpa, Tlaxcala; 2018-2020. Methods: L. squarrosa basidiomata were identified and ectomycorrhizal roots were collected and morphoanatomically characterized. For molecular identification, DNA was extracted, PCR was performed targeting the nuclear ribosomal internal transcribed spacer region (nucrDNA ITS) for the mycobiont identification and the chloroplastic single-locus trnL region for the phytobiont. Results: In the phylogenetic analyses, our sequences from basidiomata and ectomycorrhizae clustered together with L.squarrosa with high values of supporting identity. Meanwhile, P. pseudostrobus was molecularly identified as the phytobiont. Conclusions: This is one of the few worldwide characterizations of Laccaria ectomycorrhiza under field conditions and contributes to the understanding of the ecology, distribution, and economic relevance of the symbiotic association. Our data suggest that L. squarrosa has potential for use as a native inoculant for P. pseudostrobus tree production. Translate stop Translate sto