The ascorbate-glutathione cycle coming of age

Concepts, regarding the operation of the ascorbate/glutathione cycle and the associated water/water cycle in the processing of metabolically-generated hydrogen peroxide and other forms of reactive oxygen species (ROS), are well established in the literature. However, our knowledge of functions of these cycles and their component enzymes continues to grow and evolve. Recent insights include participation in the intrinsic environmental and developmental signaling pathways that regulate plant growth, development and defense. In addition to ROS processing, the enzymes of the two cycles not only support the functions of ascorbate and glutathione, they also have "moonlighting" functions. They are subject to post-translational modifications and have an extensive interactome, particularly with other signaling proteins. In this assessment of current knowledge, we highlight the central position of the ascorbate/glutathione cycle in the network of cellular redox systems that underpin the energy-sensitive communication within the different cellular compartments and integrate plant signalling pathways.</p

Plant adaptation to climate change

Plants are vital to human health and well-being, as well as helping to protect the environment against the negative impacts of climate change. They are an essential part of the 'One Health' strategy that seeks to balance and optimize the health of people, animals and the environment. Crucially, plants are central to nature-based solutions to climate mitigation, not least because soil carbon storage is an attractive strategy for mitigating greenhouse gas emissions and the associated climate change. Agriculture depends on genetically pure, high-quality seeds that are free from pests and pathogens and contain a required degree of genetic purity. This themed collection addresses key questions in the field encompassing the biochemical mechanisms that underlie plant responses and adaptations to a changing climate. This collection encompasses an analysis of the biochemistry and molecular mechanisms underpinning crop and forest resilience, together with considerations of plant adaptations to climate change-associated stresses, including drought, floods and heatwaves, and the increased threats posed by pathogens and pests.</p

Incident light orientation lets C4 monocotyledonous leaves make light work differently

Photosynthesis is an important driver of ecosystem sustainability in the face of climate change. Monocotyledonous crop species with C4 photosynthesis such as maize (Zea mays L; corn) and sugar cane are crucial for future food security and biofuel crop requirements, while C4 pasture grasses such as Paspalum are central to natural ecosystems. The global demand for corn will exceed that for wheat and rice by 2020, making it the world&#x27;s most important crop. Light-driven photosynthesis supports plant biomass production, but plants have also evolved safety valve mechanisms that attenuate the absorption of potentially lethal levels of excess light. The array of survival responses that enables leaves to evade photoinhibition is complex and involves chloroplast and leaf movement as well as the molecular rearrangements that facilitate thermal energy dissipation. Here we report a novel morphological mechanism that allows C4 monocotyledonous leaves to regulate photosynthesis independently on each surface with respect to incident light allowing better adaptation to water deficits and light stress. We show that under abaxial illumination as occurs when monocotyledonous leaves curl in response to water stress the stomata close and photosynthetic metabolism shuts down on the adaxial surface of C4 leaves but these parameters increase in function to the abaxial surface. We discuss how this regulation confers a survival advantage to the C4 relative to C3 leaves which are unable to regulate their dorso-ventral functions in relation to light

Building forests for the future

Many governments have set ambitious targets for tree planting and increased woodland cover as a key part of actions to reach net‐zero carbon emissions by 2050. However, many uncertainties remain concerning how and where to expand tree cover, what species to plant, and how best to manage new plantations. Much contemporary forestry has been based on even‐aged monocultures, largely because of perceived advantages for timber production. However, in order to play a key role in climate change mitigation future forests will have to achieve timber production (and wider ecosystem service provision) alongside resilience to biotic and abiotic challenge. It is therefore crucial that appropriate informed decisions are made with regard to the structure, composition, and planning of future forests, in order to provide sustainable solutions that provide environmental, economic, and health benefits to society. Genetically diverse, mixed, and irregular forests, with their higher biodiversity and niche complementarity, are promising new forest configurations for regulating the water cycle, storing carbon, and delivering other goods and services. In the following discussion, we have used UK information to illustrate the benefits of mixed woodland versus monocultures and highlighted current issues related to government initiatives and policies for current and future forests. However, similar issues and problems are encountered globally

Building forests for the future

Many governments have set ambitious targets for tree planting and increased woodland cover as a key part of actions to reach net‐zero carbon emissions by 2050. However, many uncertainties remain concerning how and where to expand tree cover, what species to plant, and how best to manage new plantations. Much contemporary forestry has been based on even‐aged monocultures, largely because of perceived advantages for timber production. However, in order to play a key role in climate change mitigation future forests will have to achieve timber production (and wider ecosystem service provision) alongside resilience to biotic and abiotic challenge. It is therefore crucial that appropriate informed decisions are made with regard to the structure, composition, and planning of future forests, in order to provide sustainable solutions that provide environmental, economic, and health benefits to society. Genetically diverse, mixed, and irregular forests, with their higher biodiversity and niche complementarity, are promising new forest configurations for regulating the water cycle, storing carbon, and delivering other goods and services. In the following discussion, we have used UK information to illustrate the benefits of mixed woodland versus monocultures and highlighted current issues related to government initiatives and policies for current and future forests. However, similar issues and problems are encountered globally

Editorial:Subcellular compartmentalization of plant antioxidants and ROS generating systems, volume II

JP, MR-R and FC were financed by ERDF-co-financed grants from the Junta de Andalucía (P18-FR-1359) and the Ministry of Science and Innovation (PID2019-103924GB-I00), Spain. CF was financed by BBSRC/GCRF Grant (BB/T008865/1), UK