Virus-induced gene silencing (VIGS) is a rapid reverse genetics tool that has been developed in a wide variety of plant species for assessing gene functions. However, while VIGS has been utilized successfully in the diploid model leguminous species Medicago truncatula (Gaertn.) (barrel medic), such a platform has yet to be established in forage legume crop species. Therefore, we evaluated the effectiveness of this method in forage legumes using a previously developed PEBV (pea early browning virus) system whereby a fragment of the pea (Pisum sativum L.) PHYTOENE DESATURASE (PDS) gene was transferred into a range of alfalfa (Medicago sativa L.), sainfoin (Onobrychis viciifolia Scop.), and fenugreek (Trigonella foenum-graecum L.) cultivars using leaf infiltration and apical meristem injection. Barrel medic was used as a positive control. Gene silencing was observed after 10–15 d through the presence of a leaf bleaching phenotype, and was confirmed using quantitative real-time RT-PCR. Silencing of PDS was achieved in a selection of cultivars in all species assessed, with the highest silencing efficiency apparent in fenugreek. The introduction of a highly homologous gene fragment from a heterologous plant species to target endogenous genes for transient VIGS-based silencing in a range of species of interest represents a potentially useful strategy for the rapid functional characterization of candidate genes in forages.

A continuous rise in demand for vegetable oils, which comprise mainly the storage lipid triacylglycerol, is fueling a surge in research efforts to increase seed oil content and improve fatty acid composition in oilseed crops. Progress in this area has been achieved using both conventional breeding and transgenic approaches to date. However, further advancements using traditional breeding methods will be complicated by the polyploid nature of many oilseed crops and associated time constraints, while public perception and the prohibitive cost of regulatory processes hinders the commercialization of transgenic oilseed crops. As such, genome editing using CRISPR/Cas is emerging as a breakthrough breeding tool that could provide a platform to keep pace with escalating demand while potentially minimizing regulatory burden. In this review, we discuss the technology itself and progress that has been made thus far with respect to its use in oilseed crops to improve seed oil content and quality. Furthermore, we examine a number of genes that may provide ideal targets for genome editing in this context, as well as new CRISPR-related tools that have the potential to be applied to oilseed plants and may allow additional gains to be made in the future.

Alfalfa (Medicago sativa L.) is an extensively grown perennial forage legume, and although it is relatively drought tolerant, it consumes high amounts of water and depends upon irrigation in many regions. Given the progressive decline in water available for irrigation, as well as an escalation in climate change-related droughts, there is a critical need to develop alfalfa cultivars with improved drought resilience. M. sativa subsp. falcata is a close relative of the predominantly cultivated M. sativa subsp. sativa, and certain accessions have been demonstrated to exhibit superior performance under drought. As such, we endeavoured to carry out comparative physiological, biochemical, and transcriptomic evaluations of an as of yet unstudied drought-tolerant M. sativa subsp. falcata accession (PI 641381) and a relatively drought-susceptible M. sativa subsp. sativa cultivar (Beaver) to increase our understanding of the molecular mechanisms behind the enhanced ability of falcata to withstand water deficiency. Our findings indicate that unlike the small number of falcata genotypes assessed previously, falcata PI 641381 may exploit smaller, thicker leaves, as well as an increase in the baseline transcriptional levels of genes encoding particular transcription factors, protective proteins, and enzymes involved in the biosynthesis of stress-related compounds. These findings imply that different falcata accessions/genotypes may employ distinct drought response mechanisms, and the study provides a suite of candidate genes to facilitate the breeding of alfalfa with enhanced drought resilience in the future.