See How I Eat My Greens—Autophagy in Plant Cells

Eukaryotic cells have two conserved pathways for degrading polypeptides. One is the highly selective ubiquitin–proteasome system, and the other is autophagy, a bulk degradation pathway to a lytic compartment. Autophagy in plant cells has important roles in development and responses to abiotic and biotic stresses. Furthermore, plant autophagy has been implicated in vacuole biogenesis and Golgi-independent targeting of cytoplasmic materials to vacuoles. Here I present four questions that are frequently asked by plant scientists interested in autophagy. The first question relating to tools for plant autophagy research is relatively easy to answer, while the others are open questions about regulation of autophagy, autophagic cargoes, and potential differences of plant autophagic routes from corresponding metazoan pathways. This review will discuss recent progress that may provide the answers for the latter questions.     

The theater management model of plant memory

The existence of a memory in plants raises several fundamental questions. What might be the function of a plant memory? How might it work? Which molecular mechanisms might be responsible? Here, we sketch out the landscape of plant memory with particular reference to the concepts of functioning-dependent structures and competitive coherence. We illustrate how these concepts might be relevant with reference to the metaphor of a traveling, avant-garde theater company and we suggest how using a program that simulates competitive coherence might help answer some of the questions about plant memory.     

Applications of minirhizotrons to understand root function in forests and other natural ecosystems

Minirhizotrons have proved useful to understand the dynamics and function of fine roots. However, they have been used comparatively infrequently in forests and other natural plant communities. Several factors have contributed to this situation, including anomalous root distributions along the minirhizotron surface and the difficulty of extracting data from minirhizotron images. Technical and methodological advances have ameliorated some of these difficulties, and minirhizotrons have considerable potential to address some questions of long standing interest. These questions include more fully understanding the role of roots in carbon and nutrient cycling, rates of root decomposition, responses to resource availability and the functional significance of interactions between plant roots and soil organisms. Maximizing the potential for minirhizotrons to help us better understand the functional importance of fine roots in natural plant communities depends upon using them to answer only those questions appropriate to both their inherent strengths and limitations.     

Transcriptomic analyses reveal potential mechanisms of premature senescence in hexaploid Populus

Plant Cell, Tissue and Organ Culture (PCTOC) - The important role of polyploidy in plant evolution is widely recognized. However, many questions concerning how polyploidy affects the plant...     

Gravity related features of plant growth behavior studied with rotating machines

Research in plant physiology consists mostly of studies on plant growth because almost everything a plant does is done by growing. Most aspects of plant growth are strongly influenced by the earth's gravity vector. Research on those phenomena address scientific questions specifically about how plants use gravity to guide their growth processes.     

植物体细胞原生质体遗传转化研究

重点介绍了植物体细胞原生质体遗传转化的方法和当前已经取得的成果,同时提出了目前原生质体遗传转化中存在的问题,展望了今后的工作重点。植物原生质体遗传转化的方法主要有：PEG介导转化法、电击穿孔转化法、脂质体介导转化法、农杆菌共培养转化法等。     

Fifteen compelling open questions in plant cell biology

As scientists, we are at least as excited about the open questions—the things we do not know—as the discoveries. Here, we asked 15 experts to describe the most compelling open questions in plant cell biology. These are their questions: How are organelle identity, domains, and boundaries maintained under the continuous flux of vesicle trafficking and membrane remodeling? Is the plant cortical microtubule cytoskeleton a mechanosensory apparatus? How are the cellular pathways of cell wall synthesis, assembly, modification, and integrity sensing linked in plants? Why do plasmodesmata open and close? Is there retrograde signaling from vacuoles to the nucleus? How do root cells accommodate fungal endosymbionts? What is the role of cell edges in plant morphogenesis? How is the cell division site determined? What are the emergent effects of polyploidy on the biology of the cell, and how are any such “rules” conditioned by cell type? Can mechanical forces trigger new cell fates in plants? How does a single differentiated somatic cell reprogram and gain pluripotency? How does polarity develop de-novo in isolated plant cells? What is the spectrum of cellular functions for membraneless organelles and intrinsically disordered proteins? How do plants deal with internal noise? How does order emerge in cells and propagate to organs and organisms from complex dynamical processes? We hope you find the discussions of these questions thought provoking and inspiring.

We asked 15 experts to address what they consider to be the most compelling open questions in plant cell biology and these are their questions.     

Genomics in a changing arctic: critical questions await the molecular ecologist

Molecular ecology is poised to tackle a host of interesting questions in the coming years. The Arctic provides a unique and rapidly changing environment with a suite of emerging research needs that can be addressed through genetics and genomics. Here we highlight recent research on boreal and tundra ecosystems and put forth a series of questions related to plant and microbial responses to climate change that can benefit from technologies and analytical approaches contained within the molecular ecologist's toolbox. These questions include understanding (i) the mechanisms of plant acquisition and uptake of N in cold soils, (ii) how these processes are mediated by root traits, (iii) the role played by the plant microbiome in cycling C and nutrients within high‐latitude ecosystems and (iv) plant adaptation to extreme Arctic climates. We highlight how contributions can be made in these areas through studies that target model and nonmodel organisms and emphasize that the sequencing of the Populus and Salix genomes provides a valuable resource for scientific discoveries related to the plant microbiome and plant adaptation in the Arctic. Moreover, there exists an exciting role to play in model development, including incorporating genetic and evolutionary knowledge into ecosystem and Earth System Models. In this regard, the molecular ecologist provides a valuable perspective on plant genetics as a driver for community biodiversity, and how ecological and evolutionary forces govern community dynamics in a rapidly changing climate.     

植物种质超低温保存遗传稳定性的研究进展

超低温保存被认为是种质长期保存最有效的方法,其中生物材料低温保存的遗传稳定性是植物种质资源保存中最受关注的问题之一。本文对近年来超低温保存后植物材料的遗传稳定性及变异的研究情况进行了介绍,涉及表型性状分析、基因组遗传稳定性、表观遗传变化及超低温保存的筛选效应等,为进一步研究超低温保存的应用提供参考。     

A biological framework for understanding farmers’ plant breeding

We present a framework for understanding farmer plant breeding (including both choice of varieties and populations and plant selection) in terms of the basic biological model of scientific plant breeding, focusing on three key components of that model: 1) genetic variation, 2) environmental variation and variation of genotype-by-environment interaction, and 3) plant selection. For each of these concepts we suggest questions for research on farmers’plant breeding (farmers’ knowledge, practice, and crop varieties and growing environments). A sample of recent research shows a range of explicit and implicit answers to these questions which are often contradictory, suggesting that generalizations based on experience with specific varieties, environments or farmers may not be valid. They also suggest that farmers’ practice reflects an understanding of their crop varieties and populations that is in many ways fundamentally similar to that of plant breeders; yet, is also different, in part because the details of their experiences are different. Further research based on this framework should be valuable for participatory or collaborative plant breeding that is currently being proposed to reunite farmer and scientific plant breeding.     

植物养分捕获的菌根塑性——外生菌根的塑性

植物根资源捕获塑性是地下生态学研究的重点之一, 在过去二三十年间有长足的进步。菌根塑性是根资源捕获塑性的重要方面, 但由于研究手段的限制, 目前仅有概念上的探讨。缺乏菌根塑性的根塑性研究至少是不全面的。菌根生物学的迅速发展, 尤其是分子生物学手段的介入, 使对菌根塑性进行深入研究成为可能。该文对外生菌根塑性进行讨论, 在简要介绍了外生菌根的生物学基本知识后, 着重讨论了外生菌根形态塑性和生理塑性的定义与内涵。通过文献综述, 分析讨论了外生菌根塑性的研究现状: 很少有研究聚焦在菌根塑性本身, 现有的材料多为其他研究的隐示或研究结果的引申, 并多在形态塑性方面。外生菌根的生理塑性未见有直接的实验数据。该文还对外生菌根研究中发展的、可用于菌根塑性研究的方法进行了综述。由于外生菌根塑性的复杂性, 对菌根塑性的研究会较植物根本身塑性的研究复杂得多, 问题也会相对复杂, 比如植物和外生菌根菌之间的营养需求关系、植物外生菌根塑性的生态意义、实验方法的缺陷等等。对今后外生菌根塑性研究的方向进行了探讨。     

木霉对植物的促生作用及其机制

简要回顾了木霉促进植物生长作用及其机制的研究进展,探讨了木霉促生作用的存在问题及对策,并对木霉促生作用的应用前景进行了展望。     

Rapid systemic signaling during abiotic and biotic stresses: is the ROS wave master of all trades?

Rapidly communicating the perception of an abiotic stress event, wounding or pathogen infection, from its initial site of occurrence to the entire plant, i.e. rapid systemic signaling, is essential for successful plant acclimation and defense. Recent studies highlighted an important role for several rapid whole‐plant systemic signals in mediating plant acclimation and defense during different abiotic and biotic stresses. These include calcium, reactive oxygen species (ROS), hydraulic and electric waves. Although the role of some of these signals in inducing and coordinating whole‐plant systemic responses was demonstrated, many questions related to their mode of action, routes of propagation and integration remain unanswered. In addition, it is unclear how these signals convey specificity to the systemic response, and how are they integrated under conditions of stress combination. Here we highlight many of these questions, as well as provide a proposed model for systemic signal integration, focusing on the ROS wave.     

多年生植物模式物种基因组研究的历史及进展

木本植物有许多不同于一年生草本植物的生物学特性,生物学家提出将木本植物 作为研究多年生植物的模式体系。杨属Populus树种由于研究基础较好且基因组较小,目前已 被广泛地接受作为多年生植物基因组研究的模式物种。随着杨属树种全基因组序列的测定, 杨属树种在多年生植物的功能基因组研究及一些基础科学问题的研究中将发挥重要作用。本 文综述了杨属树种基因组研究的历史、进展及将来的研究热点,旨在为我国多年生植物基因 组研究提供参考和借鉴。本文主要论述了以下几个方面的内容:（1）对杨属树种开展的细胞 遗传学研究;（2）在分子水平上对杨属树种进行的基因组研究,内容包括遗传作图、基因组 测序、物理图谱构建、基因芯片及连锁不平衡分析;（3）杨属树种基因组信息在探讨一些基 础科学问题中的潜在应用。     

Dead cells don't dance: insights from live-cell imaging in plants

Live-cell imaging has yielded surprising pictures of subcellular structures and dynamics in living plant cells. Recent studies illustrate the power of live-cell observation for revealing new biological phenomena and for generating new questions about plant cell structure and function.     

植物响应对风致机械刺激研究进展

机械刺激在自然界中是无处不在的。研究机械刺激的生态学效应有助于将风的直接效应与间接效应区别开来。机械刺激与植物生长关系的研究已经成为近年来植物生态学与植物力学研究的热点之一。从机械刺激的生态学效应及其作用机理两方面综述了国内外研究进展,为深入系统地研究植物对风区等多机械刺激干扰生境的适应性策略做了理论上的概括。同时,为这一理论的应用及未来亟待解决的主要问题进行了总结。     

Developing an ecological context for allelopathy

There has been a renewed interest in allelopathy as a plant–plant interaction as more plant ecologists have become involved in studying biological invasions. This resurgence highlights a major deficiency in our understanding of allelopathy—the lack of a well-developed ecological context for the interaction. In contrast to allelopathy, the plant–plant interaction of competition has a strong theoretical foundation as well as a large body of supporting empirical studies. We suggest that the plant-herbivore defense literature provides a mature and well-developed framework from which a broader ecological context for allelopathy can be developed. Here, we discuss three broad classes of questions, drawn from the herbivore defense literature, which may help to develop an appropriate ecological context for allelopathy. These questions focus on (1) variation in allelopathic expression within species, (2) community level variation in allelopathy across species, and (3) variation in the impacts of allelopathy on associated species. Addressing such broad population and community level themes in a variety of systems will be necessary to fully develop an ecological context for allelopathy and provide a theoretical basis for understanding its role in plant communities.     

Phylloclimate or the climate perceived by individual plant organs: what is it? How to model it? What for?

This review introduces the emergence of a new research topic, phylloclimate, located at the crossroads between ecophysiology and canopy microclimate research. Phylloclimate corresponds to the physical environment actually perceived by each individual aerial organ of a plant population, and is described by physical variables such as spectral irradiance, temperature, on-leaf water and features of around-organ air (wind speed, temperature, humidity, etc.). Knowing the actual climate in which plant organs grow may enable advances in the understanding of plant-environment interactions, as knowing surface temperature instead of air temperature enabled advances in the study of canopy development. Characterizing phylloclimate variables, using experimental work or modeling, raises many questions such as the choice of suitable space- and time-scale as well as the ability to individualize plant organs within a canopy. This is of particular importance when aiming to link phylloclimate and function-structure plant models. Finally, recent trends and challenging questions in phylloclimate research are discussed, as well as the possible applications of phylloclimate results.     

Calcium signaling in plant immunity: a spatiotemporally controlled symphony

Calcium ions (Ca²⁺) are prominent intracellular messengers in all eukaryotic cells. Recent studies have emphasized the crucial roles of Ca²⁺ in plant immunity. Here, we review the latest progress on the spatiotemporal control of Ca²⁺ function in plant immunity. We discuss discoveries of how Ca²⁺ influx is triggered upon the activation of immune receptors, how Ca²⁺-permeable channels are activated, how Ca²⁺ signals are decoded inside plant cells, and how these signals are switched off. Despite recent advances, many open questions remain and we highlight the existing toolkit and the new technologies to address the outstanding questions of Ca²⁺ signaling in plant immunity.