Intermittent streams are dynamic ecosystems that alternate between dry and wet states. Despite their global dominance, we have scant information about the effects of surface flow drying on terrestrial arthropods in channel and adjacent terrestrial habitats. In the present study, we used pitfall traps to characterise the terrestrial arthropod assemblages along lateral gradients (channel, riparian, and upland habitats) in perennial and intermittent reaches of two contrasting Mediterranean intermittent streams (Rogativa and Fuirosos streams). Simultaneously, we assessed changes in assemblage composition and structure on five sampling occasions over the entire drying period (i.e. 29 days). The composition of arthropod assemblages differed among streams, flow regimes, habitat types, and sampling dates. In contrast, depending on the stream, taxonomic richness and total abundance were similar between perennial and intermittent reaches, but differed among habitat types. Formicidae, Araneae, Collembola, and Coleoptera explained most of the differences between flow regimes and habitat types in both streams. In Rogativa stream, arthropod abundances peaked in the dry channel and increased with drying time, while abundances decreased in riparian and upland habitats. It implies that the dry channel may be colonized by riparian and upland arthropods to a greater or lesser extent depending on the stream and the specific landscape context. Our results emphasize the importance of dry channels as temporary habitats for terrestrial arthropod assemblages. Thus, the dry period should be considered explicitly when assessing biodiversity of and establishing management strategies for intermittent streams and their fringing riparian and upland areas.Values in italics indicate statistical significance at P < 0.05. GROUND-DWELLING ARTHROPOD ASSEMBLAGES IN INTERMITTENT STREAMS

Summary The cap‐binding protein eIF4E, through its interaction with eIF4G, constitutes the core of the eIF4F complex, which plays a key role in the circularization of mRNAs and their subsequent cap‐dependent translation. In addition to its fundamental role in mRNA translation initiation, other functions have been described or suggested for eIF4E, including acting as a proviral factor and participating in sexual development. We used CRISPR/Cas9 genome editing to generate melon eif4e knockout mutant lines. Editing worked efficiently in melon, as we obtained transformed plants with a single‐nucleotide deletion in homozygosis in the first eIF4E exon already in a T0 generation. Edited and non‐transgenic plants of a segregating F2 generation were inoculated with Moroccan watermelon mosaic virus (MWMV); homozygous mutant plants showed virus resistance, while heterozygous and non‐mutant plants were infected, in agreement with our previous results with plants silenced in eIF4E. Interestingly, all homozygous edited plants of the T0 and F2 generations showed a male sterility phenotype, while crossing with wild‐type plants restored fertility, displaying a perfect correlation between the segregation of the male sterility phenotype and the segregation of the eif4e mutation. Morphological comparative analysis of melon male flowers along consecutive developmental stages showed postmeiotic abnormal development for both microsporocytes and tapetum, with clear differences in the timing of tapetum degradation in the mutant versus wild‐type. An RNA‐Seq analysis identified critical genes in pollen development that were down‐regulated in flowers of eif4e/eif4e plants, and suggested that eIF4E‐specific mRNA translation initiation is a limiting factor for male gametes formation in melon.

It is well described that viral infections stimulate the emission of plant volatiles able to recruit viral vectors thereby promoting virus spread. In contrast, much less is known on the effects that emitted volatiles may have on the metabolism of healthy neighboring plants, which are potential targets for new infections through vector transmission. Watermelon mosaic virus (WMV) (genus Potyvirus, family Potyviridae) is an aphid-transmitted virus endemic in cucurbit crops worldwide. We have compared gene expression profiles of WMV infected melon plants with those of healthy or healthy-but-cohabited-with-infected plants. Pathogenesis-related (PR) and small heat shock protein encoding genes were deregulated in cohabited plants, and PR deregulation depended on the distance to the infected plant. The signaling was short distance in the experimental conditions used, and cohabiting had a moderate effect on the plant susceptibility to WMV. Static headspace experiments showed that benzaldehyde and γ-butyrolactone were significantly over-emitted by WMV-infected plants. Altogether, our data suggests that perception of a volatile signal encoded by WMV-infected tissues triggers a response to prepare healthy tissues or/and healthy neighboring plants for the incoming infections.