One of the main diseases that adversely impacts the global citrus industry is citrus bacterial canker (CBC), caused by the bacteria Xanthomonas citri subsp. citri (Xcc).  Response to CBC is a complex process, with both protein-DNA as well as protein–protein interactions for the regulatory network.  To detect such interactions in CBC resistant regulation, a citrus high-throughput screening system with 203 CBC-inducible transcription factors (TFs), were developed.  Screening the upstream regulators of target by yeast-one hybrid (Y1H) methods was also performed.  A regulatory module of CBC resistance was identified based on this system.  One TF (CsDOF5.8) was explored due to its interactions with the 1-kb promoter fragment of CsPrx25, a resistant gene of CBC involved in reactive oxygen species (ROS) homeostasis regulation.  Electrophoretic mobility shift assay (EMSA), dual-LUC assays, as well as transient overexpression of CsDOF5.8, further validated the interactions and transcriptional regulation.  The CsDOF5.8–CsPrx25 promoter interaction revealed a complex pathway that governs the regulation of CBC resistance via H₂O₂ homeostasis.  The high-throughput Y1H/Y2H screening system could be an efficient tool for studying regulatory pathways or network of CBC resistance regulation.  In addition, it could highlight the potential of these candidate genes as targets for efforts to breed CBC-resistant citrus varieties.

The cereal cyst nematodes (Heterodera avenae, Heterodera filipjevi, Heterodera latipons) are considered to be one of the most important plant parasitic nematodes attacking most cereals and can cause significant crop losses (Sikora 1988).  In China, H. filipjevi (Madzhidov 1981) Stelter, 1984, was first reported from Henan province (Peng et al. 2010) and a few years later in Anhui province and Xinjiang Uygur Autonomous Region (Peng et al. 2016, 2018) .  In December 2017, a survey for cereal cyst nematodes on winter wheat was conducted in Shandong Province, China.  A total of 79 samples that including roots and rhizosphere soil were collected.  Cysts and second-stage juveniles (J2s) were isolated from each soil sample using the sieving-decanting method.  Wheat roots were stained with acid fusion to observe the development of cereal cyst nematodes.  One sample collected from Yangzhuan Village in Huanggang Town, Shan County of Heze City (GPS 34°38´23.10´´N, 116°05´42.95´´E), Shandong Province, was found that the wheat roots were heavily parasitized by cyst nematodes, and most of the nematodes in roots had developed to fourth-stage (J4) in mid-December of 2017.  The morphological and molecular studies of cyst and J2s were carried out to confirm the identification of H. filipjevi in one winter wheat field soil and root sample from Shan County.  The cysts were lemon shaped with prominent vulval cone, brown to black in colour.  Cuticle with irregular zig-zag pattern.  Neck prominent, vulval cone bifenestrate with horseshoe-shaped fenestra, bullae and underbridge strongly developed.  The main morphometrics of cysts (n=8) were length (including neck) (688 to 948 μm, mean=794 μm, standard deviation=87 μm), width (465 to 620 μm, mean=529 μm, standard deviation=63 μm), neck length (71.5 to 126.3 μm, mean=86.5 μm, standard deviation=9.2 μm), fenestra length (43.8 to 71.3 μm, mean=58.0 μm, standard deviation=15.1 μm), fenestra width (19.8 to 32.0 μm, mean=25.0 μm, standard deviation=3.9 μm), length of vulval slit (8.1 to 9.7 μm, mean=9.1 μm, standard deviation=0.5 μm) and length of underbridge (64.5 to 101.3 μm, mean=82.6 μm, standard deviation=12.8 μm).  Measurements of J2s (n=10); body length (556.7 to 617.0 μm, mean=584.3 μm, standard deviation=23.2 μm); stylet (22.8 to 24.1 μm, mean=23.3 μm, standard deviation=0.4 μm), tail (59.6 to 68.6 μm, mean=65.8 μm, standard deviation=3.5 μm) and hyaline tail terminus (35.9 to 41.1 μm, mean=38.6 μm, standard deviation=2.1 μm).  Genomic DNA was isolated from single cysts (n=6), and the internal transcribed spacer regions were amplified with primers TW81 (5´-GTTTCCGTAGGTGAACCTGC-3´) and AB28 (5´-ATATGCTTAAGTTCAGCGGGT-3´) (Joyce et al. 1994) and 28S rDNA-D2/D3 regions were amplified with primers D2A (5´-ACAAGTACCGTGAGGGAAAGTTG-3´) and D3B (5´-TCGGAAGGAACCAGCTACTA-3´) (Subbotin et al. 2006).  The obtained internal transcribed spacer regions (ITSs) sequences (GenBank accession MG859977) is 99% identical to those of H. filipjevi from Turkey (KR704292.1 and KR704304.1), the United States (KP878490.1 and GU079654.1) and China (KY448473.1 and KY448473.1).  The obtained 28S rDNA-D2/D3 sequences (GenBank accession MG859980) also to be 99 to 100% identical to those of H. filipjevi from China (GU083597.1, KT314235.1, GU083592.1).  The species-specific primers of H. filipjevi (HfF1, 5´-CAGGACGAAACTCATTCAACCAA-3´; HfR1, 5´-AGGGCGAACAGGAGAAGATTAGA-3´) were also used to identify this population (Peng et al. 2013), the specific band was obtained species-specific primers of H. filipjevi.  Based on the morphological and molecular data, the species of the cyst-forming nematode was identified as H. filipjevi.  As far as we know, this is the first report of H. filipjevi in Shandong Province, China.  The population density of H. filipjevi were found much higher than those of other CCN, it can serious infect winter wheat at seedling stage which often cause economically damaging to wheat, so the spread of H. filipjevi would be a risk for the cereal production of Shandong province. 

Wheat (Triticum aestivum L.) quality is a major focus of wheat breeding, which is influenced by multiple factors. The Huang-Huai wheat region, one of the main wheat-producing areas in China, provides favourable conditions for cultivating wheat cultivars with strong-gluten and medium-strong-gluten. In this study, a systematic assessment of seven crucial quality traits and important genetic loci (Glu-1 and Sec-1) in 436 wheat cultivars in the Huang-Huai wheat region of China by principal component analysis (PCA) and fuzzy comprehensive evaluation (FCE) methods showed that the stability time (ST), stretch area (SA), and maximum resistance (MAXR) were identified as three key factors, which significantly influenced wheat quality. Glu-1 and Sec-1 primarily impacted these three traits and subsequently influenced wheat quality. Compared to Glu-A1 and Glu-B1, Glu-D1 has a more significant impact on the comprehensive evaluation value D, principal components PC1-PC3, and the main traits ST, SA and MAXR of PC1. Wheat cultivars carrying the high-molecular-weight glutenin subunit (HMW-GS) Dx5+Dy10 exhibited a notable improvement in ST, SA, and MAXR traits compared with those carrying HMW-GS Dx2+Dy12, suggesting that Dx5+Dy10 may enhance wheat quality by improving ST, SA, and MAXR. By combining the results of D value, GYT (genotype by yield×trait) index, and HMW-GS score, 20 high-quality and high yield wheat cultivars were identified, which can be used as elite parents for wheat quality breeding.