Annual review of plant biology最新文献

Cryo-electron tomography (cryo-ET) is a transformative technique in cell biology that enables three-dimensional visualization of cellular structures in near-native states and at nanometer and even subnanometer resolution. Unlike traditional imaging methods, cryo-ET preserves the ultrastructure of cells without chemical fixation or staining, allowing researchers to observe macromolecular complexes in situ. Cryo-focused ion beam milling has overcome sample thickness limitations, enabling high-resolution imaging of complex and large specimens. When combined with correlative light microscopy and subtomogram averaging, cryo-ET can localize and resolve macromolecular assemblies within the cell. We discuss how cryo-ET has provided unprecedented insights into cellular architecture by bridging the gap between molecular and cellular scales and highlight examples in photosynthetic organisms. We also discuss new efforts to increase automation, throughput, and validation that make cryo-ET accessible to a larger community of scientists, including plant biologists.

Membrane lipid composition underpins the structural and functional identity of all plant membranes. This review examines membrane lipid metabolism and trafficking, with an emphasis on how lipid diversity and interorganelle movement support plant cell function. We explore the biophysical and biochemical specialization of subcellular membranes, with discussion of the endoplasmic reticulum, plasma membrane, apoplastic vesicles and barriers, tonoplast, peroxisomes, mitochondria, plastids, and thylakoids. We review both vesicular and nonvesicular lipid transport pathways, including membrane contact sites. Particular attention is given to glycerolipids, including phospholipids and galactolipids, sphingolipids, sterols, and, to a lesser extent, fatty acid exchange. By focusing on mechanisms of lipid transfer and remodeling, this review synthesizes our understanding of subcellular membrane lipid composition in the context of dynamic cellular processes including cell plate expansion, environmental stress responses, and photosynthetic membrane assembly.

Phenotypic plasticity (PP) is a fundamental property of plants, enabling a single genotype to produce different phenotypes in response to environmental variation. This ability is crucial for survival and reproduction in heterogeneous habitats, allowing plants to optimize their physiology, development, and growth under changing conditions. Widespread natural genetic variation for plasticity enables selection to shape environmental responses. This review synthesizes the current knowledge on the genetic and molecular mechanisms underlying PP in plants, highlighting its importance for crop breeding and for enhancing resilience to climate change. We discuss experimental approaches to quantify plasticity and identify its genetic basis and consider factors that may constrain the evolution of plasticity. We also explore how advances in the analysis of multisite field trials and genomic prediction have propelled the study of PP in agriculture. Ultimately, a deeper understanding and targeted use of PP hold promise for developing crop varieties that can maintain stable yields in increasingly variable environments.

Inositol phosphates and pyrophosphates are small, water-soluble molecules involved in a range of physiological processes across eukaryotic organisms, including plants. Over the past two decades, significant advancements in inositol (pyro)phosphate detection and chemical synthesis, coupled with the characterization of plant mutants and the structural analysis of receptors and associated proteins, have greatly enhanced our understanding of their production, degradation, and perception in plants. This growing knowledge base demonstrates that inositol (pyro)phosphates are crucial for regulating key processes, such as phosphorus homeostasis, hormone signaling, and plant-microbe interactions. We provide a global perspective on these processes, highlighting recent discoveries, new possibilities, and unresolved questions.

Plants and microbes exchange macromolecules such as RNA and proteins. How this exchange is accomplished is poorly understood, but extracellular vesicles (EVs) have been proposed as likely vehicles. Here, we review recent work on the biogenesis and functions of plant EVs and the current evidence in support of and against their role in cross-kingdom RNA interference. Plant EVs, like EVs from other kingdoms of life, are released in part by the fusion of multivesicular bodies with the plasma membrane, a complex and conserved mechanism involving lipid-modifying proteins, the exocyst complex, and Rab GTPases. Though some plant EV subpopulations are involved in immunity, it appears unlikely that plant EVs contribute to cross-kingdom RNA interference. Recent work has shown that plants secrete extravesicular RNA, including small RNAs and long noncoding RNAs, into the leaf apoplast and onto leaf surfaces, while very little RNA is found inside of EVs. We propose that these free extracellular RNAs play a central role in maintaining a healthy leaf microbiome.

Pyrenoids are eukaryotic CO₂-fixing organelles that are evolutionarily diverse, globally abundant, and critical to global carbon cycling. Despite being described over 200 years ago, the vast majority of our molecular understanding of pyrenoids has emerged only in the past decade. Here, we review the recent advances in characterizing pyrenoid structure, function, and evolutionary variation across lineages containing primary, secondary, and tertiary plastids of both red and green origins. We outline experimental frameworks that can be used to answer key questions about these enigmatic organelles. We discuss the utility of pyrenoids as model biomolecular condensates for investigating fundamental properties of liquid-liquid phase separation. Finally, we summarize how understanding convergently evolved pyrenoids across diverse lineages may be used to advance efforts to engineer functional pyrenoids into crop plants to enhance CO₂ fixation for yield improvements and carbon dioxide removal.

Plant cells possess functionally specialized RNA polymerases (RNAPs) in both the nucleus and the chloroplast. In addition to the conserved RNA polymerase I (Pol I), Pol II, and Pol III, the nuclear genome of land plant cells encodes two unique multiple-subunit DNA-dependent RNAPs-Pol IV and Pol V-which produce noncoding RNAs for nuclear gene silencing. The plastid genome of all plant cells also encodes a unique multiple-subunit DNA-dependent RNAP-the plastid-encoded RNAP (PEP). Phylogenetic analyses indicate that these plant-specific RNAPs have clear evolutionary origins: Pol IV and Pol V diverged from Pol II, while PEP originated from cyanobacterial RNAP. Over billions of years, these plant-specific RNAPs underwent functional specialization through losing key residues, motifs, and domains essential to their ancestors' function and gaining new motifs, domains, and subunits tailored to their distinct roles. This review explores the evolutionary loss-and-gain strategy that shaped the three plant-specific RNAPs.

Developmental patterning-such as longitudinal zonation of roots in growth domains, the transversal subdivision into layers of distinct cell types, and asymmetric growth during tropisms-is inherently multiscale and multiprocess. Consequently, computational models integrating these processes and scales are powerful tools to test whether our current understanding of involved players is both necessary and sufficient. Additionally, models help identify missing factors and reveal how the whole exceeds the sum of its parts. In this review, we discuss influential models that have advanced our understanding of root development and its adaptation to environmental conditions. We also highlight the potential for further integration of growth, mechanics, physiology, and physicochemical processes in these models. Such expansions are critical to advance the explanatory power of current models beyond genetic causes and identify the importance of cell size, nutrients, forces, pH, and ionic charge for developmental processes.

Cereal root systems are critical for nutrient and water uptake as well as for anchorage and thus for plant productivity. This review synthesizes the current understanding of the morphological and cellular organization and the genetic regulation of the different cereal root types. We highlight conserved and lineage-specific developmental mechanisms across maize, rice, and barley. Genetic dissection of cereal root system formation has uncovered key regulators of root initiation and elongation as well as genes controlling root architecture via the root setpoint angle. Moreover, we discuss genes that determine cell and tissue identity and genes that link root traits to domestication. By integrating molecular genetics with developmental and evolutionary perspectives, we highlight how insights into the molecular mechanisms of root system architecture can contribute to the production of high-yielding and at the same time sustainable crops, ensuring global food security.

Root exudation is the process by which plants release organic and inorganic metabolites from their roots into the surrounding soil. Root exudation is a dynamic process and shapes plant-environment interactions at the root-soil interface. Little is known about the biological and environmental factors that shape the exuded metabolome, hereafter referred to as the exudome, despite its importance in structuring soil processes. Here, we emphasize plant physiological and morphological traits that modulate the exudome in a species- and developmental stage-specific manner. We further discuss how environmental factors drive exudation processes. We highlight evidence of a potential circadian exudation rhythm and further illustrate how the physical (temperature, structure), chemical (moisture, pH, nutrients, pollutants), and biological (micro- and macrofauna) properties of soil alter the root exudome composition and release patterns. Exploring the factors that directly or indirectly modulate exudation will enhance our understanding of how this dynamic process mediates plant-environment interactions.