Plant responses to climate change, how global warming may impact on food security: a critical review

Global agricultural production must double by 2050 to meet the demands of an increasing world human population but this challenge is further exacerbated by climate change. Environmental stress, heat, and drought are key drivers in food security and strongly impacts on crop productivity. Moreover, global warming is threatening the survival of many species including those which we rely on for food production, forcing migration of cultivation areas with further impoverishing of the environment and of the genetic variability of crop species with fall out effects on food security. This review considers the relationship of climatic changes and their bearing on sustainability of natural and agricultural ecosystems, as well as the role of omics-technologies, genomics, proteomics, metabolomics, phenomics and ionomics. The use of resource saving technologies such as precision agriculture and new fertilization technologies are discussed with a focus on their use in breeding plants with higher tolerance and adaptability and as mitigation tools for global warming and climate changes. Nevertheless, plants are exposed to multiple stresses. This study lays the basis for the proposition of a novel research paradigm which is referred to a holistic approach and that went beyond the exclusive concept of crop yield, but that included sustainability, socio-economic impacts of production, commercialization, and agroecosystem management.

Analysis of metabolic differences in maize in different growth stages under nitrogen stress based on UPLC-QTOF-MS

Introduction

Maize has a high demand for nitrogen during the growth period. The study of metabolic changes in maize can provide a theoretical basis for rational nitrogen nutrition regulation.

Methods

In order to investigate the changes of different metabolites and their metabolic pathways in maize leaves under nitrogen stress, we used ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) for metabolomic analysis of maize leaves under different nitrogen treatments at three critical growth stages (V4, V12 and R1) in a pot experiment under natural conditions.

Results and discussion

The results showed that nitrogen stress significantly affected sugar metabolism and nitrogen metabolism, and affected carbon and nitrogen balance, and the effects of stress on maize leaves metabolism increased with the growth process. Metabolic pathways such as the TCA cycle and starch and sucrose metabolism were mainly affected at the seeding stage (V4). The stress response to nitrogen deficiency also showed significant upregulation of flavonoids such as luteolin and astragalin during the booting stage (V12) and anthesis-silking stage (R1). During R1 stage, the synthesis of tryptophan and phenylalanine and the degradation of lysine were significantly affected. Compared with nitrogen stress, the metabolic synthesis of key amino acids and jasmonic acid were intensified and the TCA cycle was promoted under nitrogen sufficiency conditions. This study initially revealed that the response mechanism of maize to nitrogen stress at the metabolic level.

Towards smart and sustainable development of modern berry cultivars in Europe

Fresh berries are a popular and important component of the human diet. The demand for high-quality berries and sustainable production methods is increasing globally, challenging breeders to develop modern berry cultivars that fulfill all desired characteristics. Since 1994, research projects have characterized genetic resources, developed modern tools for high-throughput screening, and published data in publicly available repositories. However, the key findings of different disciplines are rarely linked together, and only a limited range of traits and genotypes has been investigated. The Horizon2020 project BreedingValue will address these challenges by studying a broader panel of strawberry, raspberry and blueberry genotypes in detail, in order to recover the lost genetic diversity that has limited the aroma and flavor intensity of recent cultivars. We will combine metabolic analysis with sensory panel tests and surveys to identify the key components of taste, flavor and aroma in berries across Europe, leading to a high-resolution map of quality requirements for future berry cultivars. Traits linked to berry yields and the effect of environmental stress will be investigated using modern image analysis methods and modeling. We will also use genetic analysis to determine the genetic basis of complex traits for the development and optimization of modern breeding technologies, such as molecular marker arrays, genomic selection and genome-wide association studies. Finally, the results, raw data and metadata will be made publicly available on the open platform Germinate in order to meet FAIR data principles and provide the basis for sustainable research in the future.

Leaf size modulation by cytokinins in sesame plants

Phytohormones play important roles in controlling leaf size and in the modulation of various stress responses, including drought. In this study, hormone profiling analyses by ultra high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (UHPLC-MS/MS) was performed in leaves collected at three stages of active leaf growth to unravel which phytohormones modulate leaf size in sesame (Sesamum indicum L.) plants, an important oil-rich crop. Furthermore, endogenous contents of phytohormones were measured in parallel to various stress markers in sesame plants exposed to mild water deficit conditions by withholding water in potted plants for one week. Results revealed a major role of cytokinins and auxin in the modulation of leaf growth in sesame plants (which increased by 21.5 and 2.1-fold, respectively, with leaf growth), as well as a putative antagonistic response between jasmonic acid and salicylic acid during leaf development. Furthermore, growth arrest during water deficit stress appeared to be modulated by cytokinins, the endogenous contents of which decreased (by 48%) in parallel with ABA increases (by 59%). Reductions in the contents of the active cytokinin trans-zeatin occurred in parallel with increases in isopentenyladenine contents under drought, which suggests a partial metabolic limitation in cytokinin biosynthesis in leaves upon water deficit stress. These results provide useful information for the hormonal modulation of leaf size and the improvement of leaf growth and production in sesame plants through manipulation of the levels of key regulatory phytohormones.

Shelf life of composite flour mixtures

Enrichment of food products with proteins, minerals and dietary fiber is possible by introducing grinding products of some cereal crops into wheat flour, i.e. obtaining composite flour mixtures. To date, there is a need to enrich food products with essential fatty acids, especially Linolenic acid (w-3), the deficiency of which leads to serious disruptions in functioning of the human body. Analysis of the lipid composition of various oilseed crops shows that the composition of flaxseed oil as a source of w-3 demonstrates an absolute advantage. The solution to the problem of flour enrichment with essential fatty acids is currently being solved by using crushed flaxseed cake. However, the use of flaxseed cake has several disadvantages. First of all, as studies have shown, the amount of such flaxseed flour in the composition of the composite mixture should be 15-20% to ensure the required amount in essential fatty acids, which significantly impairs the consumer properties of bread. The use of flax seeds directly will significantly reduce their proportion in the composition of the composite mixture.

Management of air flows inside steel silo during grain storage

A study was conducted concerning effects of temperature and relative air humidity during long-term storage of wheat grain in a steel silo. The study was aimed at identifying the possibility of condensed moisture appearing under the silo roof. The probable periods of condensate in the space under the silo roof depending on the temperature difference inside and outside the silo have been determined. Some ways to prevent the condensate formation are proposed in the paper.

Methodology for assessing the grain mass thermal effusivity in a metal silo under the influence of active ventilation

The purpose of studying the thermal effusivity of the grain mass in a metal silo is to obtain a dynamic mathematical model of the processes of layered changes in the temperature of the grain mass under the influence of an external factor. Such an external factor is the supply of cooling air through the air distribution grid of the bottom of the silo with the active ventilation of grain in a metal silo. The created mathematical and parametric models allow simulating the moisture transfer process using active air ventilation systems inside metal silos during storage of wheat grain. There have been developed some ways to improve the conditions for ensuring the quality preservation of grain during its long-term storage in a metal silo. It is necessary to load such a silo with grain completely, preferably up to the top, leaving free supergrannial space as small as possible. Another solution is thermal insulation of the surfaces of the silo. The task of ensuring the safety of wheat food grain can be accomplished not only on the basis of existing regulatory rules, but also by taking into account the results of new research. The main method of storage in metal containers, according to the instructions and safety regulations is the storage of grain in a dry and purified state. It is known that not only humidity and purity, but also the temperature of the grain put into storage affect the storage period.

Modernising breeding for orphan crops: tools, methodologies, and beyond

In spite of the limited investment in orphan crops, access to new technologies such as bioinformatics and low-cost genotyping opens new doors to modernise their breeding effectively. Innovation in plant breeding is imperative to meet the world's growing demand for staple food and feed crops, and orphan crops can play a significant role in increasing productivity and quality, especially in developing countries. The short breeding history of most orphan crops implies that genetic gain should be achievable through easy-to-implement approaches such as forward breeding for simple traits or introgression of elite alleles at key target trait loci. However, limited financial support and access to sufficient, relevant and reliable phenotypic data continue to pose major challenges in terms of resources and capabilities. Digitalisation of orphan-crop breeding programmes can help not only to improve data quality and management, but also to mitigate data scarcity by allowing data to be accumulated and analysed over time and across teams. Bioinformatics tools and access to technologies such as molecular markers, some of them provided as services via specific platforms, allow breeders to implement modern strategies to improve breeding efficiency. In orphan crops, more marker-trait associations relevant to breeding germplasm are generally needed, but implementing digitalization, marker-based quality control or simple trait screening and introgression will help modernising breeding. Finally, the development of local capacities-of both people and infrastructure-remains a necessity to ensure the sustainable adoption of modern breeding approaches.

Identification of Leaf Promoters for Use in Transgenic Wheat

Wheat yields have plateaued in recent years and given the growing global population there is a pressing need to develop higher yielding varieties to meet future demand. Genetic manipulation of photosynthesis in elite wheat varieties offers the opportunity to significantly increase yields. However, the absence of a well-defined molecular tool-box of promoters to manipulate leaf processes in wheat hinders advancements in this area. Two promoters, one driving the expression of sedoheptulose-1,7-bisphosphatase (SBPase) and the other fructose-1,6-bisphosphate aldolase (FBPA) from Brachypodium distachyon were identified and cloned into a vector in front of the GUS reporter gene. Both promoters were shown to be functionally active in wheat in both transient assays and in stably transformed wheat plants. Analysis of the stable transformants of wheat (cv. Cadenza) showed that both promoters controlled gus expression throughout leaf development as well as in other green tissues. The availability of these promoters provides new tools for the expression of genes in transgenic wheat leaves and also paves the way for multigene manipulation of photosynthesis to improve yields.