Thinopyrum elongatum is an important relative of wheat, it is favored by many researchers for the disease resistant genes that exist in its E genome. Some studies have showed that the 7E chromosome of Th. elongatum contains resistance genes related to Fusarium head blight and wheat rust. Therefore, developing 7E chromosome-specific molecular markers linked to resistance genes will provide an important tool for exploring and using the resistant genes of Th. elongatum. In addition, it would greatly contribute in the effort to cultivate disease-resistant wheat varieties. Featured in high throughput, high-accuracy and low-cost, SLAF-seq technology has been widely used in molecular breeding, system evolution, and germplasm resource detection. Based on SLAF-seq, 518 specific fragments on the 7E chromosome of Th. elongatum were successfully amplified. A total of 135 primers were designed according to 135 randomly selected fragments, and 89 specific molecular markers of Th. elongatum were developed, with efficiencies up to 65.9%. These markers were all detected in a variety of materials, and they are all proved to be specific and stable. These markers can be used not only for detecting the 7E chromosome of Th. elongatum but also for providing an important theoretical and practical basis for wheat breeding by marker-assisted selection (MAS). This paper reports the first application of SLAF-seq technology with a high success rate in developing specific molecular markers for Th. elongatum, providing a strong case for the application of this new technology.

Summary: Phytochrome‐interacting factors (PIFs) play major roles in regulating plant growth and development, but their roles in drought stress remain elusive. Here, we cloned and characterized a maize (Zea mays) PIF transcription factor, ZmPIF1. The expression level of ZmPIF1 was significantly induced by independent drought and abscisic acid (ABA) treatments. The ZmPIF1 transgenic rice and Arabidopsis displayed water saving and drought resistance, which were associated with reduced a stomatal aperture and transpiration rate. Moreover, the ZmPIF1 transgenic rice were hypersensitive to exogenous ABA, while the endogenous ABA level was not significantly changed, suggesting that ZmPIF1 was a positive regulator of the ABA signalling pathway. Digital gene expression (DGE) results further indicated that ZmPIF1 participated in ABA signalling pathway and regulated the stomatal aperture in rice. In addition, grain yield and agronomic traits analysis over 4 years showed that ZmPIF1 was able to increase the grain yield through an increase in tiller and panicle numbers in transgenic rice. Overall, ZmPIF1 plays an important role in the ABA‐mediated regulation of stomatal closure to control water loss. ZmPIF1 can enhance water saving and drought resistance and improve the crop yield in rice, illustrating the capacity of ZmPIF1 for crop improvement.

Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Here, excellent salt-tolerant maize inbred line TL1317 and extremely salt-sensitive maize inbred line SL1303 were screened to understand the maize response to salt stress and its tolerance mechanisms. Relative water content, membrane stability index, stomatal conductance, chlorophyll content, maximum photochemical efficiency, photochemical efficiency, shoot and root fresh/dry weight, and proline and water soluble sugar content analyses were used to identify that the physiological effects of osmotic stress of salt stress were obvious and manifested at about 3 days after salt stress in maize. Moreover, the ion concentration of two maize inbred lines revealed that the salt-tolerant maize inbred line could maintain low Na+ concentration by accumulating Na+ in old leaves and gradually shedding them to exclude excessive Na+. Furthermore, the K+ uptake and retention abilities of roots were important in maintaining K+ homeostasis for salt tolerance in maize. RNA-seq and qPCR results revealed some Na+/H+ antiporter genes and Ca2+ transport genes were up-regulated faster and higher in TL1317 than those in SL1303. Some K+ transport genes were down-regulated in SL1303 but up-regulated in TL1317. RNA-seq results, along with the phenotype and physiological results, suggested that the salt-tolerant maize inbred line TL1317 possesses more rapidly and effectively responses to remove toxic Na+ ions and maintain K+ under salt stress than the salt-sensitive maize inbred line SL1303. This response should facilitate cell homoeostasis under salt stress and result in salt tolerance in TL1317.

Cold stress is a major factor limiting rice (Oryza sativa L.) production worldwide, especially at the seedling and booting stages. Identification of genes associated with cold tolerance (CT) in rice is important for sustainable food production. Here, we report the results of a genome-wide association study (GWAS) to identify the genetic loci associated with CT by using a 1,033-accession diversity panel. We identified five CT-related genetic loci at the booting stage. Accessions carrying multiple cold-tolerant alleles displayed a higher seed setting rate than did accessions that had no cold-tolerant alleles or carried a single allele. At the seedling stage, eight genetic loci related to CT have been identified. Among these, LOC_Os10g34840 was identified as the candidate gene for the qPSR10 genetic locus that is associated with CT in rice seedlings. A single-nucleotide polymorphism (SNP), SNP2G, at position 343 in LOC_Os10g34840 is responsible for conferring cold tolerance at the seedling stage in rice. Further analysis of the haplotype network revealed that SNP2G was present in 80.08% of the temperate japonica accessions but only 3.8% of the indica ones. We used marker-assisted selection to construct a series of BC4F3 near-isogenic lines possessing the cold-tolerance allele SNP2G. When subjected to cold stress, plants carrying SNP2G survived better as seedlings and showed higher grain weight than plants with carrying the SNP2A allele. The CT-related loci identified here and the functional verification of LOC_Os10g34840 will provide genetic resources for breeding cold-tolerant varieties and for studying the molecular basis of cold tolerance in rice.