The Editorial Office of Frontiers in Plant Science would like to thank all the Chief Editors, Associate Editors and Review Editors that played an integral part in Frontiers’ innovative Collaborative Peer-Review process in 2020. In particular, we would like to recognize and thank Prof. Joshua L. Heazlewood – our now former Field Chief Editor, for his commitment, support and enthusiasm for the Plant Science field. Josh’s dedication and leadership has helped Frontiers in Plant Science become the most cited journal in the field with a strong editorial community. Looking forward, we’re excited to welcome Prof. Yunde Zhao, as our new Field Chief Editor in 2021. Having been with Frontiers in Plant Science since 2017, Yunde has contributed extensively to the development of the journal and will continue to ensure the journal goes from strength to strength.

Plant architecture is a major determinant of the resource use efficiency of crops. The architecture of a plant shows ontogenetic structural changes which are modified by multiple environmental factors: Plant canopies are exposed to natural fluctuations in light quantity and the dynamically changing canopy architecture induces local variations in light quality. Changing temperature conditions or water availability during growth additionally affect plant architecture and thus crop productivity, because plants have various options to adapt their architecture to the available resources. Meeting the challenge of ensuring food security we must understand the plant’s mechanisms for integrating and responding to an orchestra of environmental factors. ‘Virtual plants’ describe plant architecture in silico. Virtual plants have the potential to help us understanding the complex feedback processes between canopy architecture, multiple environmental factors and crop productivity. As a research tool, they have become increasingly popular within the last decade due to their great power of realistically visualizing the plant’s architecture. This Research Topic highlights current research carried out on modeling plant architecture in changing environments.

This Research Topic addresses research in genomics and biotechnology to improve the growth and quality of forest trees for wood, pulp, biorefineries and carbon capture. Forests are the world’s greatest repository of terrestrial biomass and biodiversity. Forests serve critical ecological services, supporting the preservation of fauna and flora, and water resources. Planted forests also offer a renewable source of timber, for pulp and paper production, and the biorefinery. Despite their fundamental role for society, thousands of hectares of forests are lost annually due to deforestation, pests, pathogens and urban development. As a consequence, there is an increasing need to develop trees that are more productive under lower inputs, while understanding how they adapt to the environment and respond to biotic and abiotic stress. Forest genomics and biotechnology, disciplines that study the genetic composition of trees and the methods required to modify them, began over a quarter of a century ago with the development of the first genetic maps and establishment of early methods of genetic transformation. Since then, genomics and biotechnology have impacted all research areas of forestry. Genome analyses of tree populations have uncovered genes involved in adaptation and response to biotic and abiotic stress. Genes that regulate growth and development have been identified, and in many cases their mechanisms of action have been described. Genetic transformation is now widely used to understand the roles of genes and to develop germplasm that is more suitable for commercial tree plantations. However, in contrast to many annual crops that have benefited from centuries of domestication and extensive genomic and biotechnology research, in forestry the field is still in its infancy. Thus, tremendous opportunities remain unexplored. This Research Topic aims to briefly summarize recent findings, to discuss long-term goals and to think ahead about future developments and how this can be applied to improve growth and quality of forest trees.

The onset of flowering is an important step during the lifetime of a flowering plant. During the past two decades, there has been enormous progress in our understanding of how internal and external (environmental) cues control the transition to reproductive growth in plants. Many flowering time regulators have been identified from the model plant Arabidopsis thaliana. Most of them are assembled in regulatory pathways, which converge to central integrators which trigger the transition of the vegetative into an inflorescence meristem. For crop cultivation, the time of flowering is of upmost importance, because it determines yield. Phenotypic variation for this trait is largely controlled by genes, which were often modified during domestication or crop improvement. Understanding the genetic basis of flowering time regulation offers new opportunities for selection in plant breeding and for genome editing and genetic modification of crop species.

Besides increasing crop yield to feed the growing population, improving crop quality is a challenging and key issue. Indeed, quality determines consumer acceptability and increases the attractivity of fresh and processed products. In this respect, fruit and vegetables, which represent a main source of vitamins and other health compounds, play a major role in human diet. This is the case in developing countries where populations are prone to nutritional deficiencies, but this is also a pending issue worldwide, where the growing middle class is increasingly aware and in search of healthy food. So a future challenge for the global horticultural industry will be to answer the demand for better quality food in a changing environment, where many resources will be limited. This e-collection collates state-of-the-art research on the quality of horticultural crops, covering the underlying physiological processes, the genetic and environmental controls during plant and organ development and the postharvest evolution of quality during storage and processing.