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The maize root system has been reshaped by indirect selection during global adaptation to new agricultural environments. In this study, we characterized the root systems of more than 9,000 global maize accessions and its wild relatives, defining the geographical signature and genomic basis of variation in seminal root number. We demonstrate that seminal root number has increased during maize domestication followed by a decrease in response to limited water availability in locally adapted varieties. By combining environmental and phenotypic association analyses with linkage mapping, we identified genes linking environmental variation and seminal root number. Functional characterization of the transcription factor ZmHb77 and in silico root modeling provides evidence that reshaping root system architecture by reducing the number of seminal roots and promoting lateral root density is beneficial for the resilience of maize seedlings to drought.

Wheat is a target crop within the food security context. The responses of wheat plants under elevated concentrations of CO (e[CO]) have been previously studied; however, few of these studies have evaluated several organs at different phenological stages simultaneously under free-air CO enrichment (FACE) conditions. The main objective of this study was to evaluate the effect of e[CO] in two cultivars of wheat (Triumph and Norin), analyzed at three phenological stages (elongation, anthesis, and maturation) and in different organs at each stage, under FACE conditions. Agronomic, biomass, physiological, and carbon (C) and nitrogen (N) dynamics were examined in both ambient CO (a[CO]) fixed at 415 µmol mol CO and e[CO] at 550 µmol mol CO. We found minimal effect of e[CO] compared to a[CO] on agronomic and biomass parameters. Also, while exposure to 550 µmol mol CO increased the photosynthetic rate of CO assimilation (An), the current study showed a diminishment in the maximum carboxylation (V) and maximum electron transport (J) under e[CO] conditions compared to a[CO] at physiological level in both cultivars. However, even if no significant differences were detected between cultivars on photosynthetic machinery, differential responses between cultivars were detected in C and N dynamics at e[CO]. Triumph showed starch accumulation in most organs during anthesis and maturation, but a decline in N content was observed. Contrastingly, in Norin, a decrease in starch content during the three stages and an increase in N content was observed. The amino acid content decreased in grain and shells at maturation in both cultivars, which might indicate a minimal translocation from source to sink organs. These results suggest a greater acclimation to e[CO] enrichment in Triumph than Norin, because both the elongation stage and e[CO] modified the source–sink relationship. According to the differences between cultivars, future studies should be performed to test genetic variation under

Plants program their meristem-associated developmental switches for timely adaptation to a changing environment. Potato (Solanum tuberosum L.) tubers differentiate from specialized belowground branches or stolons through radial expansion of their terminal ends. During this process, the stolon apex and closest axillary buds enter a dormancy state that leads to tuber eyes, which are reactivated the following spring and generate a clonally identical plant. The potato FLOWERING LOCUS T homolog SELF-PRUNING 6A (StSP6A) was previously identified as the major tuber-inducing signal that integrates day-length cues to control the storage switch. However, whether some other long-range signals also act as tuber organogenesis stimuli remains unknown. Here, we show that the florigen SELF PRUNING 3D (StSP3D) and FLOWERING LOCUS T-like 1 (StFTL1) genes are activated by short days, analogously to StSP6A. Overexpression of StSP3D or StFTL1 promotes tuber formation under non-inductive long days, and the tuber-inducing activity of these proteins is graft transmissible. Using the non-tuber-bearing wild species Solanum etuberosum, a natural SP6A null mutant, we show that leaf-expressed SP6A is dispensable for StSP3D long-range activity. StSP3D and StFTL1 mediate secondary activation of StSP6A in stolon tips, leading to amplification of this tuberigen signal. StSP3D and StFTL1 were observed to bind the same protein partners as StSP6A, suggesting that they can also form transcriptionally active complexes. Together, our findings show that additional mobile tuber-inducing signals are regulated by the photoperiodic pathway.

P1 is the first protein translated from the genomes of most viruses in the family Potyviridae, and it contains a C-terminal serine-protease domain that cis-cleaves the junction between P1 and HCPro in most cases. Intriguingly, P1 is the most divergent among all mature viral factors, and its roles during viral infection are still far from understood. In this study, we found that telosma mosaic virus (TelMV, genus Potyvirus) in passion fruit, unlike TelMV isolates present in other hosts, has two stretches at the P1 N terminus, named N1 and N2, with N1 harboring a Zn finger motif. Further analysis revealed that at least 14 different potyviruses, mostly belonging to the bean common mosaic virus subgroup, encode a domain equivalent to N1. Using the newly developed TelMV infectious cDNA clones from passion fruit, we demonstrated that N1, but not N2, is crucial for viral infection in both Nicotiana benthamiana and passion fruit. The regulatory effects of N1 domain on P1 cis cleavage, as well as the accumulation and RNA silencing suppression (RSS) activity of its cognate HCPro, were comprehensively investigated. We found that N1 deletion decreases HCPro abundance at the posttranslational level, likely by impairing P1 cis cleavage, thus reducing HCPro-mediated RSS activity. Remarkably, disruption of the Zn finger motif in N1 did not impair P1 cis cleavage and HCPro accumulation but severely debilitated TelMV fitness. Therefore, our results suggest that the Zn finger motif in P1s plays a critical role in viral infection that is independent of P1 protease activity and self-release, as well as HCPro accumulation and silencing suppression.

Melon (Cucumis melo L.) is an important vegetable crop that has an extensive history of cultivation. However, the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available. Here we report a chromosome-level T2T genome assembly for 821 (C. melo ssp. agrestis var. acidulus), a semi-wild melon with two haplotypes of ~373 Mb and ~364 Mb, respectively. Comparative genome analysis discovered a significant number of structural variants (SVs) between melo (C. melo ssp. melo) and agrestis (C. melo ssp. agrestis) genomes, including a copy number variation located in the ToLCNDV resistance locus on chromosome 11. Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1 (CmABA2), encoding a cytoplasmic short chain dehydrogenase/reductase, which controls the biosynthesis of abscisic acid. This study provides valuable genetic resources for future research on melon breeding.

Understanding the mechanisms underlying plant resistance to virus infections is crucial for viral disease management in agriculture. However, the defense mechanism of watermelon (Citrullus lanatus) against cucumber green mottle mosaic virus (CGMMV) infection remains largely unknown. In this study, we performed transcriptomic, metabolomic, and phytohormone analyses of a CGMMV susceptible watermelon cultivar ‘Zhengkang No.2’ (‘ZK’) and a CGMMV resistant wild watermelon accession PI 220778 (PI) to identify the key regulatory genes, metabolites, and phytohormones responsible for CGMMV resistance. We then tested several phytohormones and metabolites for their roles in watermelon CGMMV resistance via foliar application, followed by CGMMV inoculation. Several phenylpropanoid metabolism-associated genes and metabolites, especially those involved in the flavonoid biosynthesis pathway, were found to be significantly enriched in the CGMMV-infected PI plants compared with the CGMMV-infected ‘ZK’ plants. We also identified a gene encoding UDP-glycosyltransferase (UGT) that is involved in kaempferol-3-O-sophoroside biosynthesis and controls disease resistance, as well as plant height. Additionally, salicylic acid (SA) biogenesis increased in the CGMMV-infected ‘ZK’ plants, resulting in the activation of a downstream signaling cascade. SA levels in the tested watermelon plants correlated with that of total flavonoids, and SA pre-treatment up-regulated the expression of flavonoid biosynthesis genes, thus increasing the total flavonoid content. Furthermore, application of exogenous SA or flavonoids extracted from watermelon leaves suppressed CGMMV infection. In summary, our study demonstrates the role of SA-induced flavonoid biosynthesis in plant development and CGMMV resistance, which could be used to breed for CGMMV resistance in watermelon

Non-PR, IFPRI5; 3 Building Inclusive and Efficient Markets, Trade Systems, and Food Industry; 1 Fostering Climate-Resilient and Sustainable Food Supply; 2 Promoting Healthy Diets and Nutrition for all; 4 Transforming Agricultural and Rural Economies, DSGD, Remarkable achievements in global food security have been made in the past several decades. Food production has grown significantly and outpaced the population growth. Household food consumption has increased, and undernourishment has declined dramatically. However, due to multiple risks and threats such as climate change, COVID-19, environmental degradation, trade frictions, and regional conflicts, global food security and nutrition face unprecedented challenges. In fact, the number of hungry people in the world has been increasing since 2015, with more than 800 million people now suffering from hunger. After decades of development, China has ended hunger. In the new development stage, the Chinese government has proposed even higher development goals; these include Healthy China 2030, Rural Revitalization, Ecological Civilization, Common Prosperity and Carbon Neutrality.

Lettuce is one of the most commonly consumed leafy vegetables worldwide andis available throughout the entire year. Lettuce is also a significant source ofnatural phytochemicals. These compounds, including glycosylated flavonoids,phenolic acids, carotenoids, the vitamin B groups, ascorbic acid, tocopherols,and sesquiterpene lactones, are essential nutritional bioactive compounds. Thisreview aims to provide a comprehensive understanding of the composition ofhealth-promoting compounds in different types of lettuce, the potential healthbenefits of lettuce in reducing the risks of chronic diseases, and the effect ofpreharvest and postharvest practices on the biosynthesis and accumulation ofhealth-promoting compounds in lettuce.

There is an increasing demand for astaxanthin in food, feed, cosmetics and pharmaceutical applications because of its superior anti-oxidative and coloring properties. However, naturally produced astaxanthin is expensive, mainly due to low productivity and limited sources. Reprogramming of microorganisms for astaxanthin production via metabolic engineering is a promising strategy. We primarily focus on the application of synthetic biology, enzyme engineering and metabolic engineering in enhancing the synthesis and accumulation of astaxanthin in microorganisms in this review. We also discuss the biosynthetic pathways of astaxanthin within natural producers, and summarize the achievements and challenges in reprogramming microorganisms for enhancing astaxanthin production. This review illuminates recent biotechnological advances in microbial production of astaxanthin. Future perspectives on utilization of new technologies for boosting microbial astaxanthin production are also discussed.

Non-PR, IFPRI5; 3 Building Inclusive and Efficient Markets, Trade Systems, and Food Industry; DCA, DSGD, During the past several decades, significant progress has been made in reducing global hunger and malnutrition. The number of people suffering malnutrition, however, is rising again. The hidden costs and externalities in the agrifood systems are among the major contributors to various economic, social, and public health crises including food insecurity, zoonotic diseases, climate change, and malnutrition. Compounding the ongoing challenges facing the global agrifood systems, the COVID-19 pandemic, beginning in 2020, has intensified food insecurity and malnutrition in many parts of the world. Global food price indexes increased by more than 27.3 percent from the second half of 2020 to March 2021. Moreover, with many people losing their jobs during the COVID-19 outbreak and therefore facing a dramatic income decrease, the number of people confronted with food crises and extreme poverty increased significantly. Furthermore, the outbreak and prevalence of COVID-19 also increased regional inequalities in global food security, especially in Africa and the Middle East.

Potyviridae is the largest family of plant-infecting RNA viruses and includes many agriculturally and economically important viral pathogens. The viruses in the family, known as potyvirids, possess single-stranded, positive-sense RNA genomes with polyprotein processing as a gene expression strategy. The N-terminal regions of potyvirid polyproteins vary greatly in sequence. Previously, we identified a novel virus species within the family, Areca palm necrotic spindle-spot virus (ANSSV), which was predicted to encode two cysteine proteases, HCPro1 and HCPro2, in tandem at the N-terminal region. Here, we present evidence showing self-cleavage activity of these two proteins and define their cis-cleavage sites. We demonstrate that HCPro2 is a viral suppressor of RNA silencing (VSR), and both the variable N-terminal and conserved C-terminal (protease domain) moieties have antisilencing activity. Intriguingly, the N-terminal region of HCPro1 also has RNA silencing suppression activity, which is, however, suppressed by its C-terminal protease domain, leading to the functional divergence of HCPro1 and HCPro2 in RNA silencing suppression. Moreover, the deletion of HCPro1 or HCPro2 in a newly created infectious clone abolishes viral infection, and the deletion mutants cannot be rescued by addition of corresponding counterparts of a potyvirus. Altogether, these data suggest that the two closely related leader proteases of ANSSV have evolved differential and essential functions to concertedly maintain viral viability.

Background: Cucurbits produce fruits or vegetables that have great dietary importance and economic significance worldwide. The published genomes of at least 11 cucurbit species are boosting gene mining and novel breeding strategies, however genetic transformation in cucurbits is impractical as a tool for gene function validation due to low transformation efficiency. Virus-induced gene silencing (VIGS) is a potential alternative tool. So far, very few ideal VIGS vectors are available for cucurbits. Results: Here, we describe a new VIGS vector derived from cucumber green mottle mosaic virus (CGMMV), a monopartite virus that infects cucurbits naturally. We show that the CGMMV vector is competent to induce efficient silencing of the phytoene desaturase (PDS) gene in the model plant Nicotiana benthamiana and in cucurbits, including watermelon, melon, cucumber and bottle gourd. Infection with the CGMMV vector harboring PDS sequences of 69-300 bp in length in the form of sense-oriented or hairpin cDNAs resulted in photobleaching phenotypes in N. benthamiana and cucurbits by PDS silencing. Additional results reflect that silencing of the PDS gene could persist for over two months and the silencing effect of CGMMV-based vectors could be passaged. Conclusions: These results demonstrate that CGMMV vector could serve as a powerful and easy-to-use tool for characterizing gene function, controlling viral pathogens or even performing resistance breeding in cucurbits. Moreover, this study will possess considerable important reference value for developing different viral vectors.

Soil water deficit is one of the important abiotic stresses affecting vegetation restoration. The magnitude and spatiotemporal dynamics of soil water content (SWC) provide basic guidance for optimal vegetation restoration. In a semiarid Chinese area, the changes in the soil water storage (SWS) of five cultivated grasslands and one wasteland were observed, to evaluate the water consumption at different soil depths (0–100 cm), from 2008 to 2012. The plants of the three leguminous species consumed more water in deep soil layers (80–100 cm) and produced more aboveground biomass than the plants of the two gramineous species. The gramineous plants mainly consumed shallow soil water (0 ≤ 30 cm). The soil water deficit in the whole soil profile of Medicago sativa grassland (43–48%) was significantly higher than the deficit of the gramineous grasslands (p < .05). After 5 years of planting, the SWC of Agropyron cristatum grassland (21%) was the highest in the 20‐ to 80‐cm soil layer. The variation of SWS in M. sativa grassland did not significantly differ during this period, although its mean value was 28% lower than the value in A. cristatum grassland (181 mm). At the end of the experiment, leguminous grasslands caused a serious soil water shortage deficit in the 80‐ to 100‐cm soil layers. These results underscore that vegetation type determines the vertical distribution of soil water deficit, particularly in deep layers. To promote long‐term sustainability of water resources, planting A. cristatum may be a good choice for early grassland restoration in arid areas.

Drought can cause and accelerate the degradation of planted legume grassland, and the changes in plant community composition can further influence soil physical properties. Here, the soil water response of different plant functional groups (legumes, grass, and forbs) were studied along a legume grassland degradation succession according to the above-ground biomass and the proportion of each functional group. In particular, changes in the soil water storage (SWS), soil properties (soil capillary porosity (CP), and soil organic matter) and plant traits (proportion of functional groups and below-ground biomass) were quantified in a continuously cultivated legume grassland for fifteen, sixteen, eighteen, and twenty-two years, without any tillage. The experimental plots were located in the semi-arid region of the Chinese Loess Plateau, in a flat area without runoff contribution. All plant and soil samples, and measurements, were obtained in a few days to minimize the temporal variability. SWS increased at 50–150 cm soil depth when the proportion of legume functional group (LFG) decreased from 70% to 5%, and this increment was ca. 20% at 50–100 cm soil layers. The Shannon-Wiener diversity index (H), the species richness (R), LFG, CP, and the non-capillary porosity (NCP) were significantly correlated with SWS (P < 0.05). The infiltration capacity significantly improved when the proportion of LFG accounted for 5%, which favored the recharge of the soil water reservoir with rainfall. Roots decay apparently improved the soil structure, and favored water infiltration, providing a suitable condition for latter vegetation growth. This study underlined the significant interaction that exists between the plant functional groups and the soil water processes during the artificial legume grassland succession. We proved that plant composition can change the surface hydrologic cycle, and the soil water exchange, in rainfed grassland.

IFPRI1; Open Access, EPTD, This is a compiled unique long-term panel dataset that consists of data on (i) pest severity and insecticide applications per annum per county by pest species, and (ii) land cover/use data. The counties in the database are the 51 most important cotton-growing counties, by production, in the Yangtze River valley and Yellow River valley cotton production regions, while the data covered the years 1991–2015, with complete coverage of counties in all years when cotton was cultivated. Between 2011 and 2013, eight counties in our sample stopped cultivating cotton. The number increased to 11 and 12 counties in 2014 and 2015, respectively, resulting in 47 missing records. The national cotton pests monitoring network, maintained by the Ministry of Agriculture mandates the main cotton-producing counties to collect yearly data on pest infestation levels and insecticide applications for key cotton pests following national standardized monitoring and categorization methods. Tailored scouting methods were used for different pests. In each county, 10–20 fields were selected for pest monitoring in each year. Insect populations were recorded every 3–10 days from early June to late August each year, and the seasonal average abundance across the surveyed fields were used for scoring using a five-point scale of levels I–V. Data on the number of insecticide applications targeted at specific pests were collected by interviewing farmers at each scouting to estimate yearly pest-specific total number of sprays for each county. While the detailed data collection methods and protocols should inspire confidence in the data, the reliability of the pest level data depends on the accuracy, knowledge, and honesty of the respondents, as is the case with any non–first-hand data. County-level land use data were drawn from a national land cover/use database developed by the Chinese Academy of Sciences, using satellite remote-sensing data from the Landsat Thematic Mapper/Enhanced Thematic Mapper images.

[EN] A total of 144 weaned hybrid HYLA rabbits (40-day-old) were randomly divided into 4 groups, to investigate the effects of the intensity of one week’s feed restriction on short- and medium-term growth performance, blood metabolites and hepatic IGF-1 in growing rabbits. Restricted groups were fed with 30% (Group L30), 50% (Group L50) 70% (Group L70) of ad libitum feeding for 1 wk and then fed ad libitum until the end of the experiment (75 d of age). The control group (Group AL) was fed ad libitum throughout the experiment. Total feed intake (–15.8%) and feed conversion ratio (–13.2%) were lower in the L50 than in the AL group (P<0.05), but no difference was found between the L30, L70 and AL groups (P>0.05) for these parameters. Total weight gain did not significantly differ among the 4 experimental groups (38.5 g/d; P>0.05). At the end of the feed restriction period, the total serum protein level (P=0.01) was higher in restricted rabbits than AL rabbits (P<0.01), while the hepatic IGF-1 level was lower in L30 and L50 groups than in the 2 other groups (P<0.001). However, no difference remained between groups at the end of the experiment. In contrast, calcium, triglycerides, alkaline phosphatase, urea nitrogen and total cholesterol levels were similar between groups (P>0.05) throughout the experiment. In conclusion, a short-term feed restriction improves feed conversion ratio in a lasting way, transiently alters serum protein and IFG-1 levels and leads to compensatory growth in growing rabbits.

3-days Course, info:eu-repo/semantics/nonPublished