Salt-Tolerant Crops: Time to Deliver

Despite the numerous advances made in our understanding of the physiology and molecular genetics of salinity tolerance, there have been relatively few applications of these to improve the salt tolerance of crops. The most significant advances have historically utilized intraspecific variation, introgression of traits from close crop wild relatives, or, less frequently, introgression from more distant relatives. Advanced lines often fail due to difficulties in the introgression or tracking of traits or due to yield penalties associated with the alleles in nonsaline environments. However, the greatest limitation is that salinity is not a primary trait for breeders. We must close the gap between research and delivery, especially for farmers who have precious few alternatives. These efforts should include a reassessment of old techniques such as grafting current crops with salt-tolerant hybrid rootstocks. Alternatively, future crops can be produced via domestication of salt-tolerant wild species—an approach that is now feasible in our lifetime.

Decoding the Auxin Matrix: Auxin Biology Through the Eye of the Computer

The plant hormone auxin is certainly the most studied developmental regulator in plants. The many functions of auxin during development, from the embryo to the root and shoot construction, are mediated by an ever-growing collection of molecular regulators, with an overwhelming degree of both ubiquity and complexity that we are still far from fully understanding and that biological experiments alone cannot grasp. In this review, we discuss how bioinformatics and computational modeling approaches have helped in recent years to explore this complexity and to push the frontiers of our understanding of auxin biology. We focus on how analysis of massive amounts of genomic data and construction of computational models to simulate auxin-regulated processes at different scales have complemented wet experiments to increase the understanding of how auxin acts in the nucleus to regulate transcription and how auxin movement between cells regulates development at the tissular scale.

Between-Plant Signaling

Parasitic plants use a special organ, the haustorium, to attach to and penetrate host tissues, forming phloem and/or xylem fusion with the host vascular systems. Across this haustorium–host interface, not only water and nutrients are extracted from the host by the parasitic plant, but also secondary metabolites, messenger RNAs, noncoding RNAs, proteins, and systemic signals are transported between the parasite and host and even among different hosts connected by a parasite. Furthermore, mycorrhizal fungi can form common mycelial networks (CMNs) that simultaneously interconnect multiple plants. Increasing lines of evidence suggest that CMNs can function as conduits, transferring stress-related systemic signals between plants. Between-plant signaling mediated by haustoria and CMNs likely has a profound impact on plant interactions with other organisms and adaptation to environmental factors. Here, we summarize the findings regarding between-plant transfer of biomolecules and systemic signals and the current understanding of the physiological and ecological implications of between-plant signaling.