All Cover Illustrations

    Volume 23, Issue 5, May 2024

    We identiffed one lipophorin receptor-related gene (LmLRP2) and investigated its function in the migratory locust Locusta migratoria. The mRNA of LmLRP2 is widely distributed in different tissues, including integument, wing pads, foregut, midgut, hindgut, Malpighian tubules and fat body, and the amounts of LmLRP2 transcripts are decreased gradually in early stages and then increased in late stages before ecdysis during developmental stage of nymphs. The protein of LmLRP2 is located in cellular membranes of midgut and hindgut. RNAi to silence LmLRP2 caused molting defects in nymphs. Importantly, a signiffcant increase in the content of neutral lipids (diglyceride and triglyceride) in midgut and a decrease in hemolymph and fat body were observed in dsLmLRP2-injected nymphs by lipidomics analysis. In addition, we found a slight increase of cuticle surface hydrocarbons in dsLmLRP2-treated nymphs, which is probably due to stimulation of de novo lipid synthesis in the fat body or oenocytes. Taken together, our results indicate that LmLRP2 located in cellular membranes of midgut cells is required for lipid export from the midgut to the hemolymph and fat body in locusts. This study not only enriches the research content of lipid metabolism in insects, but also helps to ffnd new targets for pest control and insecticide resistance. The cover photo was provided by Dr. Yiyan Zhao, Research Institute of Applied Biology, Shanxi University, China. For more details, please see pages 1618–1633. 

    Volume 23, Issue 4, Apr. 2024

    Xinong 979 is a widely cultivated wheat elite with high yield and Fusarium head blight (FHB) resistance. However, its resistance mechanism remains unclear. Our study showed that its FHB resistance consists of two lines of defense. The first line of defense, which is constitutive, is knitted via the enhanced basal expression of lignin and jasmonic acid biosynthesis genes. The second line of defense, which is induced upon Fusarium graminearum infection, is contributed by the limited suppression of photosynthesis and the struggle of biotic stress-responding genes. This cover image illustrates insight into breeding FHB-resistant wheat, which is possible by selecting wheat lines with stronger basal defense characterized by lignin content (stained lemmas), and higher induced defense from photosynthesis (depicted by sunlight). The photo is provided by Dr. Qinhu Wang from College of Plant Protection, Northwest A&F University, China. See pages 1238–1258 for more details.

    Volume 23, Issue 3, Mar. 2024

    We initially identified differentially expressed genes (DEGs) by comparing the transcriptomes of folic acid (FA)-treated and water-treated (CK) berries at different time points, and then analyzed the sequences to detect alternatively spliced (AS) genes associated with postharvest softening. During the postharvest storage of FA-treated berries, the VvPE2 gene, which encodes a cell wall-degrading enzyme, undergoes alternative splicing giving rise to two transcripts: the full-length isoform VvPE2.1 and the alternatively spliced form VvPE2.2. VvPE2.1 possesses the complete structure of the PECTINESTERASE gene, and the encoded protein maintains full enzyme functionality, whereas VvPE2.2 encodes an incomplete protein. The up-regulation of VvPE2.2 in FA-treated berries is expected to reduce the accumulation of VvPE2.1, subsequently leading to reduced enzymatic degradation of pectin by PE, thus delaying berry softening. This study provides a comprehensive analysis of AS events in postharvest grape berries using transcriptome sequencing and underscores the pivotal role of VvPE2 during the postharvest storage of grape berries. The cover photo was provided by Dr. Maosong Pei, College of Horticulture and Plant Protection, Henan University of Science and Technology. See pages 863–875 for details.

    Volume 23, Issue 2, Feb. 2024

    Agriculture and food sector has focused on food supply until very recently.  But the sector has broader impact on peoples’ diets, nutrition and health, and the environment including climate change.   The goal of this special section includes both reviews and empirical studies on agri-food systems transformation, focusing on multiple win strategies in the transformation.  Empirical evidence in the section shows that non-farm employment, internet use and household resilience are instrumental in improving diets and nutritional health of the population, while the use of solid fuels poses a significant risk to the health of children.  On sustainability, the included papers demonstrate that policy decisions and demographic changes have important impact on food security and future greenhouse gas emissions.  On the inclusion side, the studies show that targeted programs and empowerment of marginalized groups can improve their health status and food consumption quality.  In terms of efficiency, the included paper illustrates that technology in genetic improvement can significantly improve the efficiency of agricultural food systems, which is still critical in future food systems transformation.  The cover photo is provided by Ph.D. candidate Zongyi Wu and Ph.D. candidate Jiayu Xia from China Agricultural University, Beijing, demonstrating the multiple goals of transforming agri-food systems.  See pages 355–483 for details.

    Volume 23, Issue 1, Jan. 2024

    Flower organ development in rice is closely related to yield, and its identity is mainly determined by A-, B-, C- and E-class genes, with the majority encoding MADS-box transcription factors. However, the regulatory mechanisms of these floral organ signature genes during flower development remains to be clarified. In this study, we successfully identified SPW2, which ecodes a plant-specific EMF1- like protein that involved in the H3K27me3 modification as an important component of the PRC2 complex. We demonstrated that SPW2 can mediate the process of H3K27me3 modification of pistil- related genesOsMADS3OsMADS13OsMADS58, and DLto regulate their expression in non- pistil organs of spikelets in rice, which expands our understanding of the molecular mechanism by which SPW2 regulates floral organ identity genes through epigenetic regulation. The cover photo illustrates the abnormal phenotypes of spw2, provided by professor Li Yunfeng’s research group from Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, China.

    Volume 22, Issue 12, Dec. 2023

    Rural areas in Asian developing countries have undergone significant transformations in recent decades. This special focus aims to systematically review studies on rural transformation, shedding light on the trajectories and outcomes of this process across regions (such as provinces or districts) in China, Indonesia, and Pakistan. Empirical evidence reveals a consistent trend of transitioning agriculture from traditional to high-value practices and rural labor from farm-centric to non-farm activities over the past few decades. However, the pace of rural transformation varies considerably among countries and even within regions of a single country. Notably, accelerated rural transformation correlates with faster and more inclusive economic growth, ultimately contributing to poverty reduction. While rural transformation brings positive outcomes for women, including increased employment opportunities and empowerment, it also introduces challenges such as unstable income sources and heightened workloads. The articles delve into the probable impacts of rural institutions, policies, and investments (IPIs) on the pathways and consequences of rural transformation. Accompanying the special focus is a photo illustrating the various stages of rural transformation in Asia, contributed by Prof. Jikun Huang of Peking University and Prof. Abedullah Anjum of the Pakistan Institute of Development Economics. For further details, refer to pages 3565–3637.

    Volume 22, Issue 10, Oct. 2023

    The development of the kernel is closely related to the yield, mining essential genes for kernel development and analyzing molecular mechanisms serve as the foundation for achieving high-yield molecular breeding in maize. In this study, we successfully cloned Dek219 (Defective kernel219), a pivotal gene involved in maize kernel development, from a mutant with defective kernels. This gene encodes the DICER-LIKE1 protein, which is an essential enzyme in miRNA biogenesis. Furthermore, Dek219 is among the targets of selection during maize domestication, and natural variations in Dek219 are significantly associated with maize kernel length. We have also identified the excellent natural alleles and germplasm resources of Dek219, which provide important theoretical support and valuable gene resources for the cultivation of improved varieties of high-yield maize. The cover photo illustrates the process of breeding high-yield maize varieties with excellent allelic germplasm of Dek219, provided by Dr. Xie Sidi and Dr. Tian Ran from State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, China. See pages 2961–2980 for details.

    Volume 22, Issue 9, Sept. 2023

    Anhui Province is one of the regions with the most abundant resources of tea varieties in China, with its local varieties and ancient tea plants resources widely distributed and a long history of cultivation.  However, the large number of tea plant germplasm resources have not been collected, protected and utilized.  Therefore, the construction of core collection can not only improve the quality and efficiency of germplasm resources management, but also provide theoretical basis and core materials for the exploration of excellent gene resources.  In this study, genetic analysis on a large tea population consisting of 573 accessions including the ancient tea plants, landraces and cultivars in Anhui Province was performed using 60 SSR markers.  Moreover, a core collection contained 115 tea plant individuals was conducted, which conserved the whole genetic diversity but accounting for only 20% of the original germplasm resources.  The cover photo describes the tea plant germplasm resource bank, the phenotypes of three excellent varieties and an ancient tea plant, provided by the research team of Prof. Wei Chaoling from Anhui Agricultural University, China.  See pages 2719–2728 for details.

    Volume 22, Issue 8, Aug. 2023

    Schrankia costaestrigalis is a newly-reported potato pest in southern China.  The larvae damage potato tubers by feeding on tubers and foliage, either in the field or during storage.  The pest has caused great economic losses to farmers in the winter and early-spring potato planting areas.  Early-warning monitoring of this pest could protect domestic potato production.  Based on the environmental data (temperature and precipitation variables) and human influence index, the optimal species distribution model was used to estimate the potential geographical distribution in China under climate change.  Results showed that highly suitable habitats of S. ostaestrigalis were mainly located in Guangxi, Guangdong, Hong Kong, Fujian and Hainan.  The potential geographical distribution of S. ostaestrigalis in China will decrease under climate change, which shows a general tendency to move northeast and to the middle-high latitudes in the 2030s.  The agricultural practice of plastic film mulching in potato fields will provide a favorable microclimate for S. ostaestrigalis in the suitable areas.  More attention should be paid to the early warning and monitoring of S. ostaestrigalis in order to prevent its further spread in the China’s winter potato planting regions.  The cover photo depicts the developmental stages of S. ostaestrigalis, which is provided by Dr. Xian Xiaoqing and Ph D student Zhao Haoxiang from Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing.  See pages 2441–2455 for details.

    Volume 22, Issue 7, Jul. 2023

    Porcine reproductive and respiratory syndrome (PRRS) is a highly pathogenic infectious disease caused by PRRS virus (PRRSV). In our study, we reported the use of two precise CRISPR/Cas9 editing systems to identify important CD163 residues involved in PRRSV infection. From a dual-sgRNA editing system, we obtained the immortalized porcine alveolar macrophage (IPAM) cell lines with 40-residue (residues 523–562) deletion in CD163. From a CRISPR/Cas9-mediated HDR-based biallelic editing system, we generated precisely-edited cloned pigs with a single arginine (R) to alanine (A) substitution at position 561 of CD163 (CD163R561A), and PAMs were isolated from these CD163R561A pigs. PRRSV infection experiments showed that the IPAM cell line with the 40-residue deletion in CD163 were completely resistant to PRRSV-WUH3 (genotype 2 PRRSV) infection, and that CD163-R561A PAMs showed significantly lower susceptibility to PRRSV-WUH3 infection. Through this study, we believe that CD163 residues 523–562 are essential residues that mediate PRRSV infection, and that R561 is an important residue involved in PRRSV infection. Our study offers a valuable reference for exploring the mechanism of CD163-mediated PRRSV infection and provides other potential target sites for the generation of PRRSV-resistant CD163 gene-edited pigs. The cover photo depicts the CD163 specific edited pigs are resistant to PRRSV, which is provided by Dr. Xu Kui from Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing. See pages 2188–2199 for details.

    Volume 22, Issue 6, Jun. 2023

    High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. Based on an analysis of this mutant, we demonstrated that the Dy10 subunit is essential for maintaining dough strength. Furthermore, the Dy10-null allele positively affects the biscuit-making quality of wheat dough, making it potentially useful for soft wheat breeding programs. The cover photo depicts the formation process of wheat end-use quality, provided by the research team of Prof. Qi Pengfei and Dr. Wang Yan from Triticeae Research Institute, Sichuan Agricultural University, China. See pages 1609–1617 for details.

    Volume 22, Issue 5, May 2023

    Microwave treatment has been applied to flaxseed to achieve the efficient release of nutrients, inactivation of enzymes and improvement of flavor, etc.  However, it was still undefined how the techno-functionality of flaxseed protein changed upon microwave exposure.  We mainly elucidated how the antioxidant and interface properties changed for flaxseed protein based on the in-situ structural remodeling.  After microwave exposure, the storage protein was subjected to more compact assembly and subsequent permeation by membrane fragments of oil bodies in flaxseed.  Microwave exposure led to the retention of specific phenolic acids and promotion of antioxidant activities for flaxseed protein.  Improving oil–water interface activities of flaxseed protein produced the emulsion droplets with descending sizes and dense interface coating.  The current study could provide theoretical basis for tailoring the application functionality of protein fractions in flaxseed.  The photo depicts the potential changes in gas– and oil–water interface behavior of flaxseed protein after microwave exposure, provided by the research team of Dr. Deng Qianchun from Oil Crops Research Institute, Chinese Academy of Agricultural Sciences.  See pages 1574–1589 for details.  

    Volume 22, Issue 4, Apr. 2023

    Online automated identification of farmland pests is an important auxiliary means of pest control. In practical applications, the online insect identification system is often unable to locate and identify the target pest accurately due to factors such as small target size, high similarity between species and complex backgrounds. To facilitate the identification of insect larvae, a two-stage segmentation method, MRUNet, was proposed in this study. We conducted model training and comparative testing of MRUNet and previous methods on a semantic segmentation dataset of nine common farmland pest larvae. The experimental results show that the proposed two-stage image segmentation strategy is effective in dealing with small targets in complex backgrounds. This study provides a reliable reference for the automated identification of insect larvae. The cover photo shows the workflow of the proposed two-stage segmentation strategy and the structure of MRUNet, which is provided by Dr. Qiao Xi and Dr. Wang Fukuan from Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, China. See pages 1117–1130 for more details.

    Volume 22, Issue 3, Mar. 2023

    Arbuscular mycorrhizal fungi (AMF) help plants acquire phosphorus (P) from the soil. Cotton responds poorly to P-fertilizer application and lacks the ability to obtain P from sparingly soluble P sources, making it likely that cotton crucially depends on the AMF symbiosis. In this study, we addressed the role of mycorrhizal root traits and explored the interplay of root and mycorrhizal traits in enhancing P acquisition. We found that the more recent accessions had smaller root diameters, acquired less P, and produced less biomass at intermediate soil P levels, indicating an inadvertent varietal selection for thinner roots that provided less cortical space for AMF which then increased the need for a high P-fertilizer level. We conclude that selection for cotton should consider both morphological and mycorrhizal root traits when breeding for high-yielding cotton varieties. The photo depicts the carbon and P exchange between plants and AMF. The image was provided by MSc Ma Ruonan and Prof. Feng Gu from the College of Resources and Environmental Sciences, China Agricultural University, China. See pages 701–715 for details.

    Volume 22, Issue 2, Feb. 2023

    The melon fly Zeugodacus cucurbitae (Coquillett) is a very destructive tephritid pest across the world. Maleness-on-the-Y (MoY) is a primary factor that regulates sex determination in Ceratitis capitata and is supposed to be conserved in tephritid fruit flies. To investigate whether MoY plays a role in male sex determination of Z. cucurbitae, we examined the expression pattern of ZcMoY during embryogenesis and transiently inhibited ZcMoY in early embryos by RNAi. The expression pattern and knockdown phenotypes of ZcMoY indicate that ZcMoY plays a key role in regulating sex determination of Z. cucurbitae males. Our findings will help the understanding of sex determination in Z. cucurbitae and facilitate the development of genetic sexing strains in its biological control. The photo that depicts the morphology of a Z. cucurbitae female adult is provided by Associate Professor Lin Xianwu from the School of Plant Protection, Hainan University, China. See pages 505–513 for details