Dry-hot wind stress causes losses in wheat productivity in major growing regions worldwide, especially winter wheat in the Huang-Huai-Hai Plain of China, and both the occurrence and severity of such events are likely to increase with global climate change.  To investigate the recovery of physiological functions and yield formation using a new non-commercial chemical regulator (NCR) following dry-hot wind stress, we conducted a three-year field experiment (2018–2021) with sprayed treatments of tap water (control), monopotassium phosphate (CKP), NCR at both the jointing and flowering stages (CFS), and NCR only at the jointing stage (FSJ) or flowering stage (FSF).  The leaf physiology, biomass accumulation and translocation, grain-filling process, and yield components in winter wheat were assessed.  Among the single spraying treatments, the FSJ treatment was beneficial for the accumulation of dry matter before anthesis, as well as larger increases in the maximum grain-filling rate and mean grain-filling rate.  The FSF treatment performed better in maintaining a high relative chlorophyll content as indicated by the SPAD value, and a low rate of excised leaf water loss in flag leaves, promoting dry matter accumulation and the contribution to grain after anthesis, prolonging the duration of grain filling, and causing the period until the maximum grain-filling rate reached earlier.  The CFS treatment was better than any other treatments in relieving the effects of dry-hot wind.  The exogenous NCR treatments significantly increased grain yields by 12.45–18.20% in 2018–2019, 8.89–13.82% in 2019–2020, and 8.10–9.00% in 2020–2021.  The conventional measure of the CKP treatment only increased grain yield by 6.69% in 2020–2021.  The CFS treatment had the greatest mitigating effect on yield loss under dry-hot wind stress, followed by the FSF and FSJ treatments, and the CKP treatment only had a minimal effect.  In summary, the CFS treatment could be used as the main chemical control measure for wheat stress resistance and yield stability in areas with a high incidence of dry-hot wind.  This treatment can effectively regulate green retention and the water status of leaves, promote dry matter accumulation and efficient translocation, improve the grain-filling process, and ultimately reduce yield losses.

Lodging is a primary factor limiting rice grain yield. How to achieve the synergistic improvement of high yield and nitrogen use efficiency without lodging has always been the focus worldwide.  In this study, Yongyou 2640 (indica-japonica hybrid rice) and Jinxiangyu 1 (inbred japonica rice) were used as materials for field experiments across two years. Six different nitrogen managements were set up, including no nitrogen (T1), conventional urea (T2), controlled-release nitrogen (T3), reduction of controlled-release nitrogen (T4), controlled-release nitrogen combined with one-time basal conventional urea (T5), controlled-release nitrogen combined with split conventional urea (T6).  The results showed that compared with T2, the combined application strategy of controlled-release nitrogen (T5 and T6) could improve nitrogen use efficiency and grain yield by 4.89–5.69% and 3.41–4.65%, respectively.  The carbohydrate contents of the second basal internode, the internode breaking strength, the thickness of the epidermal silicon layer, the number of large and small vascular bundles, and the thickness of parenchymatous tissue and mechanical tissue were increased, whereas the internode length, bending moment and lodging index were reduced under the combined application strategy of controlled-release nitrogen.  These results indicated that the combined application strategy of controlled-release nitrogen could achieve the goal of high yield and nitrogen use efficiency with synchronously increased stem strength due to the improvement in the morphological, mechanical, physicochemical and anatomical properties of second basal stem.

The evaluation of plant stress tolerance and the screening of key regulatory genes under the combined stresses of high temperature and drought are important for the study of plant stress tolerance mechanisms. In this study, the drought tolerance of five grape varieties was evaluated under high-temperature conditions to screen key genes for further exploration of resistance mechanisms. By comparing and analysing the morphological characteristics and physiological indicators associated with the response of grapevines to drought stress and integrating them with the membership function to assess the strength of their drought tolerance, the order of drought tolerance was found to be as follows: 420A>110R>CS>fercal>188-08. To further analyse the mechanism of differences in drought tolerance, transcriptomic sequencing was performed on the drought-tolerant cultivar 420A, the drought-sensitive cultivar 188-08 and the control cultivar CS. The functional analysis of differential metabolic pathways indicated that the differentially expressed genes were enriched mainly in biological that 420A had higher antioxidant activity. Moreover, the transcription factors which differentially expressed were also analysed in the five grape varieties, and several genes, such as VvAGL15, VvLBD41, and VvMYB86, appeared to be closely related to drought tolerance, suggesting their potential involvement in the regulation of grapevine drought tolerance and their value in drought tolerance research.

The developmental capacity of in vitro embryos is critical for the success of embryonic biotechnology. However, in vitro embryos often exhibit suboptimal quality, with fewer inner cell mass (ICM) cells and reduced total blastocyst cell counts compared to in vivo embryos. To address this, we optimized the conventional PZM-3 culture medium by supplementing 50% Advanced DMEM/F12 and 5% FBS on the fifth day after embryo activation (Day 5 medium) and resulted in a 2.5-fold increase in the total cell numbers of parthenogenetic activation (PA) derived blastocysts. Further enhancement was achieved by incorporating Activin A in Day 5 medium, creating the OIVC (Optimized In Vitro Culture) medium, which significantly increased both the total cell numbers and the ICM cell counts by 4.5-fold in the blastocyst stage. The OIVC medium also improved the quality of pig somatic cloned and in vitro fertilized (IVF) embryos. RNA sequencing analysis revealed that in the OIVC-treated embryos, most of the differentially expressed genes were downregulated compared to the control group, with the main enriched signaling pathways including Activin A/TGF-β. Notably, among these downregulated genes, PAX6 may be as a potential key gene influencing the number of ICM cells. This study presents a novel culture system that markedly enhances pig in vitro embryo quality, providing an efficient strategy for generating cloned pigs based on somatic cell nuclear transfer (SCNT) technology.

African swine fever (ASF) is an acute, hemorrhagic disease caused by the African swine fever virus (ASFV), with a mortality up to 100%. The disease poses a seriously threat to the global swine industry, yet no commercial vaccines or antiviral drugs are available other than in Vietnam. ASFV attenuation through serial passages is a key approach for vaccine development. In this study, a cell-adapted virus, named HLJ18/BK33, was successfully generated by serially passaging the ASFV Pig/HLJ/18 in wild boar kidney cells (BK2258). This adapted virus exhibited clear cytopathic effects (CPE) and replicated stably and efficiently in BK2258 cells and porcine alveolar macrophages. Whole-genome sequence analysis revealed that, compared with the Pig/HLJ/18 virus, HLJ18/BK33 had a large deletion of 6162 bp from sites 181,027 to 187,188, and four single nucleotide deletions that led to frameshift mutations, resulting in the truncated expression of three open reading frames (ORFs) (ASFV_G_ACD_00120, ASFV_G_ACD_00350, and A179L), and the fusion expression of two ORFs (MGF_110-14L and MGF_110-11L). Additionally, four genes exhibited missense mutations, leading to single amino acid changes. Five pigs intramuscularly inoculated with 10⁶ TCID₅₀ of HLJ18/BK33 remained healthy with normal body temperatures and no clinical signs, indicating a high attenuation of virulence for HLJ18/BK33 in pigs. Upon challenge with the parental Pig/HLJ/18 virus, four of the five inoculated pigs developed persistent high fever and ASF-related clinical signs and died within 13 days of the challenge; the remaining pig developed transient fever but survived until the end of the observation period. These results indicate that the HLJ18/BK33 virus is highly attenuated but cannot induce protection against the parental virulent virus. Even though the HLJ18/BK33 virus is not a good vaccine candidate, its stable replication and distinct CPE in BK2258 cells as well as its low biosafety risk make it a valuable resource for studies on virus-host interactions, antiviral drug screening, diagnostic methods, and biological characteristics.