Citrus yellow vein clearing virus (CYVCV) is a new citrus virus that has become an important factor restricting the development of China’s citrus industry, and the CYVCV coat protein (CP) is associated with viral pathogenicity.  In this study, the Eureka lemon zinc finger protein (ZFP) ClDOF3.4 was shown to interact with CYVCV CP in vivo and in vitro.  Transient expression of ClDOF3.4 in Eureka lemon induced the expression of salicylic acid (SA)-related and hypersensitive response marker genes, and triggered a reactive oxygen species burst, ion leakage necrosis, and the accumulation of free SA.  Furthermore, the CYVCV titer in ClDOF3.4 transgenic Eureka lemon plants was approximately 69.4% that in control plants 6 mon after inoculation, with only mild leaf chlorotic spots observed in those transgenic plants.  Taken together, the results indicate that ClDOF3.4 not only interacts with CP but also induces an immune response in Eureka lemon by inducing the SA pathways.  This is the first report that ZFP is involved in the immune response of a citrus viral disease, which provides a basis for further study of the molecular mechanism of CYVCV infection.

Legume cultivars affect N uptake, component crop growth, and soil physical and chemical characteristics in maize–legume intercropping systems.  However, how belowground interactions mediate root growth, N fixation, and nodulation of different legumes to affect N uptake is still unclear.  Hence, a two-year experiment was conducted with five planting patterns, i.e., maize–soybean strip intercropping (IMS), maize–peanut strip intercropping (IMP), and corresponding monocultures (monoculture maize (MM), monoculture soybean (MS), and monoculture peanut (MP)), and two N application rates, i.e., no N fertilizer (N–) and conventional N fertilizer (N+), to examine relationships between N uptake and root distribution of crops, legume nodulation and soil N availability.  Results showed that the averaged N uptake per unit area of intercrops was significantly lower than the corresponding monocultures.  Compared with the monoculture system, the N uptake of the intercropping systems increased by 31.7–45.4% in IMS and by 7.4–12.2% in IMP, respectively.  The N uptake per plant of intercropped maize and soybean significantly increased by 61.6 and 31.8%, and that of intercropped peanuts significantly decreased by 46.6% compared with the corresponding monocultures.  Maize and soybean showed asymmetrical distribution of roots in strip intercropping systems.  The root length density (RLD) and root surface area density (RSAD) of intercropped maize and soybean were significantly greater than that of the corresponding monocultures.  The roots of intercropped peanuts were confined, which resulted in decreased RLD and RSAD compared with the monoculture.  The nodule number and nodule fresh weight of soybean were significantly greater in IMS than in MS, and those of peanut were significantly lower in IMP than in MP.  The soil protease, urease, and nitrate reductase activities of maize and soybean were significantly greater in IMS and IMP than in the corresponding monoculture, while the enzyme activities of peanut were significantly lower in IMP than in MP.  The soil available N of maize and soybean was significantly greater increased in IMS and IMP than in the corresponding monocultures, while that of IMP was significantly lower than in MP.  In summary, the IMS system was more beneficial to N uptake than the IMP system.  The intercropping of maize and legumes can promote the N uptake of maize, thus reducing the need for N application and improving agricultural sustainability.

In the past decade, there has been extensive global surveillance for highly pathogenic avian influenza (HPAI) infection in both animals and humans, however, few studies on epidemiology of avian influenza in Democratic People’s Republic of Korea (DPRK) were published.  During the period 2013–2014, HPAI H5N1 viruses were detected with outbreaks in domestic poultry in DPRK.  Phylogenetic analysis revealed that the hemagglutinin gene of all samples belonged to clade 2.3.2.1c with high homology.  The HPAI H5N1 virus found in ducks at the Tudan Duck Farm in 2013 was might introduced by migratory birds and then led to the outbreaks on neighboring chicken farms in 2014.  These data provide direct evidence for the transmission of avian influenza viruses from wild birds to waterfowl to terrestrial birds.  Therefore, the monitoring and control of influenza virus in ducks must be given top priority, which are essential components to prevent and control HPAI.

The GDSL esterase/lipase family contains many functional genes that perform important biological functions in growth and development, morphogenesis, seed oil synthesis, and defense responses in plants.  The expression of GDSL esterase/lipase genes can respond to biotic and abiotic stresses.  Although GDSL esterase/lipase family genes have been identified and studied in other plants, they have not been identified and their functions remain unclear in tomato.  This study is the first to identify 80 GDSL esterase/lipase family genes in tomato, which were named SlGELP1–80.  These genes were mapped to their positions on the chromosomes and their physical and chemical properties, gene structure, phylogenetic relationships, collinear relationships, and cis-acting elements were analyzed.  The spatiotemporal expression characteristics of the SlGELP genes in tomato were diverse.  In addition, RNA-seq analysis indicated that the expression patterns of the SlGELP genes in tomato differed before and after inoculation with Stemphylium lycopersici.  qRT-PCR was used to analyze the expression of five SlGELP genes after treatments with S. lycopersici, salicylic acid and jasmonic acid.  Finally, this study was the first to identify and analyze GDSL esterase/lipase family genes in tomato via bioinformatics approaches, and these findings provide new insights for improving the study of plant disease resistance.

Understanding the waxy maize starch physicochemical properties response to heat stress during grain filling could improve starch quality. The effects of heat stress during early (1–15 days after pollination, DAP) and late (16–30 DAP) grain filling stages on the starch physicochemical properties of four waxy maize varieties were evaluated. Crystallinity only increased in Suyunuo 5 after exposure to high temperature at late grain filling stage. The effects of heat stress on digestibility and swelling power were dependent on varieties and stages. Generally, swelling power was increased by heat stress at early grain development stage and digestibility was increased by high temperature at late grain filling stage, respectively. The results of correlation analysis indicated the starch with large granule size could swell well and easy digest. Peak, trough, final, and breakdown viscosities in response to heat stress were dependent on stages and varieties. In general, peak, trough and final viscosities were decreased and increased by heat stress at early grain formation and late grain filling stages, respectively; whereas the breakdown and setback viscosities were similar among the three treatments. Heat stress increased the gelatinization temperatures and retrogradation percentage. Gelatinization range decreased under heat stress at 1–15 DAP but remained constant under heat stress at 16–30 DAP in all varieties. The starch exposed to high temperature at 16–30 DAP presented higher digestibility and peak viscosity and lower retrogradation percentage than those at 1–15 DAP. Therefore, heat stress at early grain formation stage severely affects the physicochemical properties of starch.