ABSTRACT

Recently, there has been a remarkable increase in rice production owing to genetic improvement and increase in application of synthetic fertilizers. For sustainable agriculture, there is dire need to maintain a balance between profitability and input cost. To meet the steady growing demands of the farming community, researchers are utilizing all available resources to identify nutrient use efficient germplasm, but with very little success. Therefore, it is essential to understand the underlying genetic mechanism controlling nutrients efficiency, with the nitrogen use efficiency (NUE) being the most important trait. Information regarding genetic factors controlling nitrogen (N) transporters, assimilators, and remobilizers can help to identify candidate germplasms via high-throughput technologies. Large-scale field trials have provided morphological, physiological, and biochemical trait data for the detection of genomic regions controlling NUE. The functional aspects of these attributes are time-consuming, costly, labor-intensive, and less accurate. Therefore, the application of novel plant breeding techniques (NPBTs) with context to genome engineering has opened new avenues of research for crop improvement programs. Most recently, genome editing technologies (GETs) have undergone enormous development with various versions from Cas9, Cpf1, base, and prime editing. These GETs have been vigorously adapted in plant sciences for novel trait development to insure food quantity and quality. Base editing has been successfully applied to improve NUE in rice, demonstrating the potential of GETs to develop germplasms with improved resource use efficiency. NPBTs continue to face regulatory setbacks in some countries due to genome editing being categorized in the same category as genetically modified (GM) crops. Therefore, it is essential to involve all stakeholders in a detailed discussion on NPBTs and to formulate uniform policies tackling biosafety, social, ethical, and environmental concerns. In the current review, we have discussed the genetic mechanism of NUE and NPBTs for crop improvement programs with proof of concepts, transgenic and GET application for the development of NUE germplasms, and regulatory aspects of genome edited crops with future directions considering NUE.

摘要

最近，由于遗传改良和合成肥料应用的增加，水稻产量显着增加。对于可持续农业，迫切需要在盈利能力和投入成本之间保持平衡。为了满足农业社区不断增长的需求，研究人员正在利用所有可用资源来确定营养利用有效的种质，但收效甚微。因此，有必要了解控制养分效率的潜在遗传机制，其中氮利用效率 (NUE) 是最重要的性状。有关控制氮 (N) 转运蛋白、同化因子和再动员因子的遗传因素的信息可以帮助通过高通量技术识别候选种质。大规模的田间试验提供了形态学、用于检测控制 NUE 的基因组区域的生理和生化特征数据。这些属性的功能方面是耗时、昂贵、劳动密集型和不太准确的。因此，将新型植物育种技术（NPBT）与基因组工程结合起来，为作物改良项目开辟了新的研究途径。最近，基因组编辑技术 (GETs) 经历了巨大的发展，出现了从 Cas9、Cpf1、碱基和原始编辑等各种版本。这些 GET 已在植物科学中得到大力应用，以开发新的性状，以确保食物的数量和质量。碱基编辑已成功应用于提高水稻的 NUE，证明了 GET 开发具有提高资源利用效率的种质的潜力。由于基因组编辑被归类为与转基因 (GM) 作物相同的类别，NPBT 在一些国家继续面临监管挫折。因此，有必要让所有利益相关者参与关于 NPBT 的详细讨论，并制定解决生物安全、社会、伦理和环境问题的统一政策。在当前的综述中，我们讨论了 NUE 和 NPBT 用于作物改良计划的遗传机制，并通过概念证明、转基因和 GET 应用以开发 NUE 种质，以及基因组编辑作物的监管方面以及考虑 NUE 的未来方向。必须让所有利益相关者参与关于 NPBT 的详细讨论，并制定统一的政策来解决生物安全、社会、伦理和环境问题。在当前的综述中，我们讨论了 NUE 和 NPBT 用于作物改良计划的遗传机制，并通过概念证明、转基因和 GET 应用以开发 NUE 种质，以及基因组编辑作物的监管方面以及考虑 NUE 的未来方向。必须让所有利益相关者参与关于 NPBT 的详细讨论，并制定统一的政策来解决生物安全、社会、伦理和环境问题。在当前的综述中，我们讨论了 NUE 和 NPBT 用于作物改良计划的遗传机制，并通过概念证明、转基因和 GET 应用以开发 NUE 种质，以及基因组编辑作物的监管方面以及考虑 NUE 的未来方向。