Rice paddies are a major source of methane emissions. To meet the food demand of the growing population and to cope with global warming, reducing greenhouse gases and enhancing yields are critical. Here we demonstrate that a loss-of-function rice allele, gs3, mitigates methane emissions from methanogens by allocating more photosynthates to the grain and less to the root and increases yield by enlarging grain size and weight.

Agriculture is the second most important greenhouse gas (GHG: methane (CH₄) and nitrous oxide (N₂O) emissions)-emitting sector after the energy sector. Agriculture is also recognized as the source and sink of GHGs. The share of agriculture to the global GHG emission records has been widely investigated, but the impact on our food production systems has been overlooked for decades until the recent climate crisis. Livestock production and feed, nitrogen-rich fertilizers and livestock manure application, crop residue burning, as well as water management in flood-prone cultivation areas are components of agriculture that produce and emit most GHGs. Although agriculture produces 72–89% less GHGs than other sectors, it is believed that reducing GHG emissions in agriculture would considerably lower its share of the global GHG emission records, which may lead to enormous benefits for the environment and food production systems. However, several diverging and controversial views questioning the actual role of plants in the current global GHG budget continue to nourish the debate globally. We must acknowledge that considering the beneficial roles of major GHGs to plants at a certain level of accumulation, implementing GHG mitigation measures from agriculture is indeed a complex task. This work provides a comprehensive review of agriculture-related GHG production and emission mechanisms, as well as GHG mitigation measures regarded as potential solutions available in the literature. This review also discusses in depth the significance and the dynamics of mitigation measures regarded as game changers with a high potential to enhance, in a sustainable manner, the resilience of agricultural systems. Some of the old but essential agricultural practices and livestock feed techniques are revived and discussed. Agricultural GHG mitigation approaches discussed in this work can serve as game changers in the attempt to reduce GHG emissions and alleviate the impact of climate change through sustainable agriculture and informed decision-making.

Bakanae disease is a fungal disease of rice (Oryza sativa L.) caused by the pathogen Gibberella fujikuroi (also known as Fusarium fujikuroi). This study was carried out to identify novel quantitative trait loci (QTLs) from an indica variety Zenith. We performed a QTL mapping using 180 F_2:9 recombinant inbred lines (RILs) derived from a cross between the resistant variety, Zenith, and the susceptible variety, Ilpum. A primary QTL study using the genotypes and phenotypes of the RILs indicated that the locus qBK1^z conferring bakanae disease resistance from the Zenith was located in a 2.8 Mb region bordered by the two RM (Rice Microsatellite) markers, RM1331 and RM3530 on chromosome 1. The log of odds (LOD) score of qBK1^z was 13.43, accounting for 30.9% of the total phenotypic variation. A finer localization of qBK1^z was delimited at an approximate 730 kb interval in the physical map between Chr01_1435908 (1.43 Mbp) and RM10116 (2.16 Mbp). Introducing qBK1^z or pyramiding with other previously identified QTLs could provide effective genetic control of bakanae disease in rice.

In the current study, we used a linkage mapping–Genome-Wide Association Study (GWAS) joint strategy to investigate quantitative trait loci (QTLs) governing rice grain shape and weight in a doubled haploid (DH) population, using Kompetitive Allele-Specific PCR (KASP) markers. Results revealed the co-detection of the QTLs, qGLE-12-1 and qGLE-12-2 (Chromosome 12), qGTE-3-1 (Chromosome 3), and qGWL-5-1 and qLWRL-5-1 (Chromosome 5), associated with grain length, width, and length–width ratio, by both linkage mapping and GWAS. In addition, qGLL-7-1 (logarithm of the odds (LOD): 18.0, late-transplanted rice) and qGLE-3-1 (LOD: 8.1, early-transplanted rice), and qLWRL-7-1 (LOD: 34.5), detected only by linkage mapping, recorded a high phenotypic variation explained (PVE) of 32.5%, 19.3%, and 37.7% for grain length, and grain length–width ratio, respectively, contributed by the allele from 93-11. Meanwhile, qGWL-5-1 (LOD: 17.2) recorded a high PVE (31.7%) for grain width, and the allele from Milyang352 contributed to the observed phenotypic variation. Furthermore, qGTL-5-1 (LOD: 21.9) had a high PVE (23.3%) for grain thickness. Similarly, qTGWE-5-1 (LOD: 8.6) showed a high contribution to the PVE for grain weight (23.4%). Moreover, QTLs, qGW-5-1, qGT-5-1, qLWR-5-1, and qTGW-5-1 coincided on chromosome 5, flanked with KJ05_17 and KJ05_13 markers. Therefore, these QTLs are suggested to govern rice grain shape and weight. Additionally, the identified candidate genes could play active roles in the regulation of rice grain shape and weight, regarding their predicted functions, and similarity with previously reported genes. Downstream breeding and functional studies are required to elucidate the roles of these candidate genes in the regulation of grain shape and weight in rice.

Leaf senescence is the final stage of plant development. Many internal and external factors affect the senescence process in rice (Oryza sativa L.). In this study, we identified qCC2, a major quantitative trait locus (QTL) for chlorophyll content using a population derived from an interspecific cross between O. sativa (cv. Hwaseong) and Oryza grandiglumis. The O. grandiglumis allele at qCC2 increased chlorophyll content and delayed senescence. GW2 encoding E3 ubiquitin ligase in the qCC2 region was selected as a candidate for qCC2. To determine if GW2 is allelic to qCC2, a gw2-knockout mutant (gw2-ko) was examined using a dark-induced senescence assay. gw2-ko showed delayed leaf senescence in the dark with down-regulated expression of senescence-associated genes (SAGs) and chlorophyll degradation genes (CDGs). The association of the GW2 genotype with the delayed senescence phenotype was confirmed in an F₂ population. RNA-seq analysis was conducted to investigate 30-day-old leaf transcriptome dynamics in Hwaseong and a backcross inbred line—CR2002—under dark treatment. This resulted in the identification of genes involved in phytohormone signaling and associated with senescence. These results suggested that transcriptional regulation was associated with delayed senescence in CR2002, and RING-type E3 ubiquitin ligase GW2 was a positive regulator of leaf senescence in rice.

Nitrogen (N) is a gas and the fifth most abundant element naturally found in the atmosphere. N’s role in agriculture and plant metabolism has been widely investigated for decades, and extensive information regarding this subject is available. However, the advent of sequencing technology and the advances in plant biotechnology, coupled with the growing interest in functional genomics-related studies and the various environmental challenges, have paved novel paths to rediscovering the fundamentals of N and its dynamics in physiological and biological processes, as well as biochemical reactions under both normal and stress conditions. This work provides a comprehensive review on multiple facets of N and N-containing compounds in plants disseminated in the literature to better appreciate N in its multiple dimensions. Here, some of the ancient but fundamental aspects of N are revived and the advances in our understanding of N in the metabolism of plants is portrayed. It is established that N is indispensable for achieving high plant productivity and fitness. However, the use of N-rich fertilizers in relatively higher amounts negatively affects the environment. Therefore, a paradigm shift is important to shape to the future use of N-rich fertilizers in crop production and their contribution to the current global greenhouse gases (GHGs) budget would help tackle current global environmental challenges toward a sustainable agriculture.