Xiaowei, a New Rice Germplasm for Large-Scale Indoor Research
Xiaowei, a New Rice Germplasm for Large-Scale Indoor Research
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小味，一种用于大规模室内研究的新水稻种质
DOI：
10.1016/j.molp.2018.08.003
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发表时间：
2018-11-05
期刊：
影响因子：
27.5
通讯作者：
Qian, Qian
中科院分区：
文献类型：
--
作者：
Hu, Shikai;Hu, Xingming;Qian, Qian
水稻基因组相对较小，种质资源丰富，转化方法高效，是单子叶植物生物学研究的模式植物。尽管水稻基因组学和功能基因组学研究取得了重大进展(Li等人，2018年)，但由于水稻生长周期长，对自然环境的极端依赖，更好地了解水稻生物学的大规模室内研究受到阻碍。有一些水稻种质生育期短、株高短，如在北京栽培的抽穗期64.5±1.8d、株高71.8±2.3 cm的北大科，中国，但不能满足大规模室内种植的要求，即生物量增加，空间利用减少。在这里，我们报道了一种新的水稻种质的特征和一个不依赖于水稻生长的自然环境的理想的水稻室内研究系统(IIRS)的建立(图1 A)。我们通过在日本稻甲烷磺酸乙酯(EMS)诱变文库中筛选数以万计的水稻种质获得了一个新的水稻种质小卫。小卫植株表现为超矮型，株高(22.2±0.2 cm)仅为野生型的32.3%(图1B和1D-G及补充表1)。与野生型日本晴相比，小尾草的生长期更短，生物量更低，空间利用率更高(图1G)。这些植物可以在室内大量种植，并以类似于拟南芥植物的方式进行精确评估，因此可以用于建立水稻研究的IIRS。我们比较了小微和日本的容积率，发现小微的空间利用率显著高于日本。在相同蓄积量(体积=长3宽3高=1.3m30.5m32.0m=1.3m~3)条件下，日本防风的容积率为0.040625(0.65m~2/16株=0.040625)，小尾松为0.0008125(0.65m~2/800株=0.0008125)，是日本防风的50倍。我们在一个20平方米的栽培室里成功地培育了12000只小微个体，每个机架有15个机架，每个机架4个机架，每个机架800个个体(图1 D-1F)，允许在室内种植大量水稻。由于不可控的环境条件对水稻整个生命周期的表型和生理参数的强烈不利影响，对水稻的一些重要性状，如耐逆性和植物-病原菌相互作用的基础研究是具有挑战性的。然而，在IIRS中，温度和光照强度以及各种胁迫处理等生长条件可以得到精确控制(补充表2)。因此，IIRS是通过正向遗传突变开展水稻基础研究的一个极好的选择
Rice (Oryza sativa) is a model monocot plant for biological studies due to its relatively small genome, rich germplasm resources, and high-efficiency transformation methods. Although significant progress has been made in rice genomics and functional genomics research (Li et al., 2018), large-scale indoor research toward better understanding of rice biology is hampered by its long growth period and extreme dependence on the natural environment for cultivation. There are some rice germplasms that have a short growth period and short plant height, such as Kitaake, which has a heading date of 64.5±1.8 days and a plant height of 71.8±2.3 cm when cultivated in Beijing, China, but they cannot meet the requirements for large-scale indoor planting, namely increased biomass and reduced space utilization. Here, we report the characterization of a new rice germplasm and the establishment of an ideal indoor research system (IIRS) for rice research that does not rely on the natural environment for rice growth (Figure 1 A).We obtained a new rice germplasm, Xiaowei, by screening tens of thousands of rice germplasms in a japonica Nipponbare ethyl methanesulfonate (EMS) mutagenesis library. Xiaowei plants displayed a super-dwarf phenotype, with a plant height (22.2±0.2 cm) that was only 32.3% that of the wild type (Figure 1 B and 1D–G and Supplemental Table 1). Xiaowei plants also have a shorter growth period, lower biomass, and higher space utilization compared with the wild-type Nipponbare (Figure 1 G). These plants can be cultivated indoors in large numbers and evaluated precisely in a manner similar to Arabidopsis plants, and thus could be used for establishing IIRS for rice research. We compared the plot ratios of Xiaowei and Nipponbare, and found that the space utilization of Xiaowei was significantly higher than that of Nipponbare. In planting racks with the same volume (volume= length 3 width 3 height= 1.3 m 3 0.5 m 3 2.0 m= 1.3 m3), the plot ratio of Nipponbare was 0.040625 (0.65 m2/16 individuals= 0.040625), while that of Xiaowei was 0.0008125 (0.65 m2/800 individuals= 0.0008125); ie, 50 times more than that of Nipponbare. We successfully cultivated 12 000 Xiaowei individuals in a 20 m2 planting culture room containing 15 racks, with four levels per rack and 800 individuals per level (Figure 1 D–1F), allowing large populations of rice to be planted indoors. It is challenging to perform basic studies on some important traits, such as stress tolerance and plant–pathogen interactions, in rice grown in the paddy field due to the strongly adverse effects of uncontrollable environmental conditions on phenotypic and physiological parameters throughout the plant’s lifecycle. However, growth conditions such as temperature and light intensity and various stress treatments can be controlled precisely in the IIRS (Supplemental Table 2). Thus, the IIRS represents an excellent alternative for carrying out basic research in rice via forward genetic mutant