Hill Camilla B, Li Chengdao
Western Barley Genetics Alliance, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth WA, Australia.
Western Barley Genetics Alliance, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, PerthWA, Australia; Department of Agriculture and Food Western Australia, South PerthWA, Australia.
Front Plant Sci. 2016 Dec 19;7:1906. doi: 10.3389/fpls.2016.01906. eCollection 2016.
Cereal crop species including bread wheat ( L.), barley ( L.), rice ( L.), and maize ( L.) provide the bulk of human nutrition and agricultural products for industrial use. These four cereals are central to meet future demands of food supply for an increasing world population under a changing climate. A prerequisite for cereal crop production is the transition from vegetative to reproductive and grain-filling phases starting with flower initiation, a key developmental switch tightly regulated in all flowering plants. Although studies in the dicotyledonous model plant build the foundations of our current understanding of plant phenology genes and regulation, the availability of genome assemblies with high-confidence sequences for rice, maize, and more recently bread wheat and barley, now allow the identification of phenology-associated gene orthologs in monocots. Together with recent advances in next-generation sequencing technologies, QTL analysis, mutagenesis, complementation analysis, and RNA interference, many phenology genes have been functionally characterized in cereal crops and conserved as well as functionally divergent genes involved in flowering were found. Epigenetic and other molecular regulatory mechanisms that respond to environmental and endogenous triggers create an enormous plasticity in flowering behavior among cereal crops to ensure flowering is only induced under optimal conditions. In this review, we provide a summary of recent discoveries of flowering time regulators with an emphasis on four cereal crop species (bread wheat, barley, rice, and maize), in particular, crop-specific regulatory mechanisms and genes. In addition, pleiotropic effects on agronomically important traits such as grain yield, impact on adaptation to new growing environments and conditions, genetic sequence-based selection and targeted manipulation of phenology genes, as well as crop growth simulation models for predictive crop breeding, are discussed.
谷类作物品种，包括面包小麦（Triticum aestivum L.）、大麦（Hordeum vulgare L.）、水稻（Oryza sativa L.）和玉米（Zea mays L.），为人类提供了大部分营养以及用于工业用途的农产品。这四种谷物对于满足在气候变化情况下不断增长的世界人口未来的粮食供应需求至关重要。谷类作物生产的一个先决条件是从营养生长阶段过渡到生殖生长和籽粒灌浆阶段，始于花的起始，这是所有开花植物中严格调控的关键发育转变。尽管在双子叶模式植物中的研究为我们当前对植物物候基因和调控的理解奠定了基础，但水稻、玉米以及最近面包小麦和大麦的具有高可信度序列的基因组组装，现在使得能够在单子叶植物中鉴定与物候相关的基因直系同源物。连同下一代测序技术、QTL分析、诱变、互补分析和RNA干扰方面的最新进展，许多物候基因已在谷类作物中得到功能表征，并且发现了参与开花的保守以及功能上有差异的基因。响应环境和内源性触发因素的表观遗传和其他分子调控机制在谷类作物的开花行为中产生了巨大的可塑性，以确保仅在最佳条件下诱导开花。在本综述中，我们总结了开花时间调节因子的最新发现，重点是四种谷类作物品种（面包小麦、大麦、水稻和玉米），特别是作物特异性调控机制和基因。此外，还讨论了对诸如谷物产量等重要农艺性状的多效性影响、对适应新生长环境和条件的影响、基于遗传序列的选择和物候基因的靶向操作，以及用于预测作物育种的作物生长模拟模型。
