A modified intron of VRT2 drives glume and grain elongation in wheat.
A modified intron of VRT2 drives glume and grain elongation in wheat.
复制标题
VRT2 的修饰内含子可驱动小麦的颖片和籽粒伸长。
DOI：
10.1016/j.molp.2021.08.016
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发表时间：
2021
期刊：
影响因子：
27.5
通讯作者：
Dixon LE
中科院分区：
文献类型：
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作者：
Dixon LE
产量是一个复杂的性状，主要由植物产生的谷物的数量，大小和重量决定，这些都受到多个基因和环境因素的影响。在谷物中，谷粒大小受环境信号（包括养分可用性和温度）以及控制谷粒尺寸或花器官大小的基因变异的影响（例如，Heang和Sassa，2012; Brinton等人，2017; Adamski等人，2021; Liu等人，2021; Xiao等人，2021年）。最近的三项研究已经调查了产生较长谷粒的四倍体和六倍体小麦的亚种，所述谷粒形成为包含伸长的花结构的小花（Adamski等人，2021; Liu等人，2021; Xiao等人，2021年）;他们的发现为控制小花结构的基因提供了新的理解，育种者可以利用这些基因来提高籽粒大小和产量。在小麦中，产生籽粒的小花形成于小穗内，小穗由三到四朵小花组成，小花被一种被称为颖片的改良的叶状结构所包围。Liu et al.（2021）和Adamski et al.（2021），被称为波兰小麦或波兰小麦，其特征在于具有较长颖片的小穗的发育和细长谷粒的产生。延伸的颖片和谷粒的基础似乎与细胞大小有关，颖片和果皮的细胞都比野生型样姊妹系的细胞长（Adamski等人，2021; Liu等人，2021年）。波兰小麦较长的颖片与被称为外稃和内稃的延伸的花器官的形成有关，外稃和内稃在谷粒发育时形成包裹物（图1）。人们很容易提出，波兰小麦的谷粒生长更长，因为小花腔中谷粒发育和生长的空间位阻更少，复制了在水稻中观察到的类似现象（Heang和Sassa，2012）。较长的颖片也可能贡献本文未研究的其他有益的农艺性状，例如为发育中的谷粒提供更大的光合资源，类似于小麦中芒的所提出的功能（Rebetzke et al.，2016年）。
Yield is a complex trait that is determined predominantly by the number, size, and weight of grain produced by a plant, which are all influenced by multiple genes and environmental factors. In cereals, grain size is influenced by environmental signals including nutrient availability and temperature, and by variation for genes that control the dimensions of a grain or the size of floral organs (eg, Heang and Sassa, 2012; Brinton et al., 2017; Adamski et al., 2021; Liu et al., 2021; Xiao et al., 2021). Three recent studies have investigated subspecies of tetraploid and hexaploid wheat that produce longer grains, which form in florets that contain elongated floral structures (Adamski et al., 2021; Liu et al., 2021; Xiao et al., 2021); their findings provide new understanding of the genes controlling floret architecture, which could be used by breeders to enhance grain size and yield.In wheat, the grain-producing florets form within spikelets, which are composed of three to four florets subtended by a modified leaf-like structure called a glume (Figure 1). The tetraploid wheat analyzed by Liu et al.(2021) and Adamski et al.(2021), known as Polish wheat or Triticum polonicum, is characterized by the development of spikelets with longer glumes and the production of elongated grain. The basis of the extended glumes and grain appears to be linked to cell size, with cells of both the glumes and pericarp being longer than those of wildtype-like sibling lines (Adamski et al., 2021; Liu et al., 2021). The longer glumes of Polish wheat are associated with the formation of extended floral organs called lemma and palea, which form an envelope around the grain as it develops (Figure 1). It is tempting to propose that the grain grow longer in Polish wheat because there is less steric hindrance on grain development and growth within the floret cavity, replicating a similar phenomenon observed in rice (Heang and Sassa, 2012). The longer glumes may also contribute other beneficial agronomic traits not studied here, such as providing greater photosynthetic resource to the developing grain, similar to a proposed function of awns in wheat (Rebetzke et al., 2016).