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Summary: Germplasm resources serve as the foundations of advancements in breeding and are crucial for maintaining food security. Wild rice species of the genus Oryza include rich sources of genetic diversity and high adaptability, making them a substantial resource for rice breeding. The discovery of wild‐type cytoplasmic male sterility resources enabled the achievement of the 'three lines' goal in hybrid rice, significantly increasing rice yields. The application of resistance alleles from wild rice enables rice production to withstand losses caused by stress. Reduced genetic diversity due to rice breeding poses a significant limitation to further advances and can be alleviated through a systematic use of wild genetic resources that integrate geographic, climatic and environmental data of the original habitat, along with extensive germplasm collection and identification using advanced methods. Leveraging technological advancements in plant genomics, the understanding of genetic mechanisms and the application of artificial intelligence and gene editing can further enhance the efficiency and accuracy of this process. These advancements facilitate rapid isolation and functional studies of genes, and precise genome manipulation. This review systematically summarizes the utilization of superior genes and germplasm resources derived from wild rice sources, while also exploring the collection, conservation, identification and utilization of further wild rice germplasm resources. A focus on genome sequencing and biotechnology developments is leading to new breeding and biotechnology opportunities. These new opportunities will not only promote the development of rice varieties that exhibit high yields, superior stress resistance and high quality but also expand the genetic diversity among rice cultivars. [ABSTRACT FROM AUTHOR]

Summary: Lesion‐mimic mutants (LMMs) provide a valuable tool to reveal the molecular mechanisms determining programmed cell death (PCD) in plants. Despite intensive research, the mechanisms behind PCD and the formation of lesions in various LMMs still remain to be elucidated. Here, we identified a rice (Oryza sativa) LMM, early lesion leaf 1 (ell1), cloned the causal gene by map‐based cloning, and verified this by complementation. ELL1 encodes a cytochrome P450 monooxygenase, and the ELL1 protein was located in the endoplasmic reticulum. The ell1 mutant exhibited decreased chlorophyll contents, serious chloroplast degradation, upregulated expression of chloroplast degradation‐related genes, and attenuated photosynthetic protein activity, indicating that ELL1 is involved in chloroplast development. RNA sequencing analysis showed that genes related to oxygen binding were differentially expressed in ell1 and wild‐type plants; histochemistry and paraffin sectioning results indicated that hydrogen peroxide (H2O2) and callose accumulated in the ell1 leaves, and the cell structure around the lesions was severely damaged, which indicated that reactive oxygen species (ROS) accumulated and cell death occurred in the mutant. TUNEL staining and comet experiments revealed that severe DNA degradation and abnormal PCD occurred in the ell1 mutants, which implied that excessive ROS accumulation may induce DNA damage and ROS‐mediated cell death in the mutant. Additionally, lesion initiation in the ell1 mutant was light dependent and temperature sensitive. Our findings revealed that ELL1 affects chloroplast development or function, and that loss of ELL1 function induces ROS accumulation and lesion formation in rice. Significance Statement: ELL1 affects chloroplast development or function, and loss of ELL1 function induces ROS accumulation and lesion formation in rice. [ABSTRACT FROM AUTHOR]

Summary: The palea and lemma (hull) are grass‐specific organs, and determine grain size and quality. In the study, AH2 encodes a MYB domain protein, and functions in the development of hull and grain. Mutation of AH2 produces smaller grains and alters grain quality including decreased amylose content and gel consistency, and increased protein content. Meantime, part of the hull lost the outer silicified cells, and induces a transformation of the outer rough epidermis to inner smooth epidermis cells, and the body of the palea was reduced in the ah2 mutant. We confirmed the function of AH2 by complementation, CRISPR‐Cas9, and cytological and molecular tests. Additionally, AH2, as a repressor, repress transcription of the downstream genes. Our results revealed that AH2 plays an important role in the determination of hull epidermis development, palea identity, and grain size. Significance Statement: AH2 plays an important role in the determination of hull epidermis development, palea identity, and grain size. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is one of the most important cereal crops in the world. The identification of sd1 mutants in rice resulted in a semi-dwarf phenotype that was used by breeders to improve yields. Investigations of sd1 mutants initiated the "green revolution" for rice and staved off famine for many people in the 1960s. The smaller plant height conferred by sd1 allele gives the plants lodging resistance even with a high amount of nitrogen fertilizer. Guang-chang-ai-carrying sd1 was the first high-yielding rice variety that capitalized on the semi-dwarf trait, aiming to significantly improve the rice yield in China. IR8, known as the miracle rice, was also bred by using sd1. The green revolution gene sd1 in rice has been used for decades, but was not identified for a long time. The SD1 gene encodes the rice Gibberellin 20 oxidase-2 (GA20ox2). As such, the SD1 gene is instrumental in uncovering the molecular mechanisms underlying gibberellin biosynthesis There are ten different alleles of SD1. These alleles are identified by genome sequencing within several donor lines in breeding for semi-dwarf rice. Apart from breeding applications and the molecular mechanism of GA biosynthesis, the SD1 gene is also involved in the molecular regulation of other important agronomic traits, like nitrogen fertilizer utilization. The dentification of new alleles of SD1 can be obtained by mutagenesis and genome editing. These new alleles will play an important role in improving the resource diversity of semi-dwarf breeding in the future. [ABSTRACT FROM AUTHOR]