Identification of QTL and underlying genes for root system architecture associated with nitrate nutrition in hexaploid wheat

The root system architecture(RSA) of a crop has a profound effect on the uptake of nutrients and consequently the potential yield. However, little is known about the genetic basis of RSA and resource adaptive responses in wheat(Triticum aestivum L.). Here, a high-throughput germination paper-based plant phenotyping system was used to identify seedling traits in a wheat doubled haploid mapping population, Savannah×Rialto. Significant genotypic and nitrate-N treatment variation was found across the population for seedling traits with distinct trait grouping for root size-related traits and root distribution-related traits. Quantitative trait locus(QTL) analysis identified a total of 59 seedling trait QTLs. Across two nitrate treatments, 27 root QTLs were specific to the nitrate treatment. Transcriptomic analyses for one of the QTLs on chromosome 2 D, which was found under low nitrate conditions, revealed gene enrichment in N-related biological processes and 28 differentially expressed genes with possible involvement in a root angle response. Together, these findings provide genetic insight into root system architecture and plant adaptive responses to nitrate, as well as targets that could help improve N capture in wheat.

Chasing the mechanisms of ecologically adaptive salinity tolerance

Plants adapted to challenging environments offer fascinating models of evolutionary change. Importantly,they also give information to meet our pressing need to develop resilient, low-input crops.With mounting environmental fluctuation—including temperature, rainfall, and soil salinity and degradation—this is more urgent than ever. Happily, solutions are hiding in plain sight: the adaptive mechanismsfrom natural adapted populations, once understood, can then be leveraged. Much recent insighthas come from the study of salinity, a widespread factor limiting productivity, with estimates of 20% ofall cultivated lands affected. This is an expanding problem, given increasing climate volatility, rising sealevels, and poor irrigation practices. We therefore highlight recent benchmark studies of ecologicallyadaptive salt tolerance in plants, assessing macro- and microevolutionary mechanisms, and therecently recognized role of ploidy and the microbiome on salinity adaptation. We synthesize insightspecifically on naturally evolved adaptive salt-tolerance mechanisms, as these works move substantiallybeyond traditional mutant or knockout studies, to show how evolution can nimbly ‘‘tweak’’ plantphysiology to optimize function. We then point to future directions to advance this field that intersectevolutionary biology, abiotic-stress tolerance, breeding, and molecular plant physiology.

Global wild rice germplasm resources conservation alliance:World Wild-Rice Wiring

Wild relatives of crop are key genetic resources serving as diversity reservoirs for crop improvement under changing environments.Rice(Oryza sativa)is one of the most important crops in the world,providing staple food for half of the world's population.Wild rice is thus a critical germplasm resource for sustained global food security,ensuring high production yields,improved quality,and stress resistance in the face of climate change.Wild rice is closely related to domesticated rice and has a rich genetic diversity and exceptional adaptability to extreme environments.It has played a pivotal role in the history of rice hybridization and has become a key resource for rice breeding programs.The identification of wild-type cytoplasmic male sterility resources paved the way for the achievement of the“three lines”goal in hybrid rice,leading to a significant increase in rice yields.In addition,the use of resistance alleles found in wild rice is making rice production more resilient to losses caused by environmental stresses.However,wild rice germplasm resources are threatened due to habitat destruction and other anthropogenic factors.At the same time,the lack of centralized distribution of wild rice has hampered the sharing of basic information on wild rice resources and the utilization and conservation of wild rice in each country,as well as collaboration among scientists.