HWA1- and HWA2-Mediated Hybrid Weakness in Rice Involves Cell Death, Reactive Oxygen Species Accumulation, and Disease Resistance-Related Gene Upregulation
HWA1- and HWA2-Mediated Hybrid Weakness in Rice Involves Cell Death, Reactive Oxygen Species Accumulation, and Disease Resistance-Related Gene Upregulation
复制标题
DOI：
10.3390/plants8110450
复制
发表时间：
2019-11-01
期刊：
影响因子：
4.5
通讯作者：
Tezuka, Takahiro
中科院分区：
文献类型：
--
作者：
Shiragaki, Kumpei;Iizuka, Takahiro;Tezuka, Takahiro
杂种弱是一种生殖隔离，正常亲本的F-1杂种表现出比其亲本弱的生长特性。印度稻品种“P.T.B.7”和“A.D.T.14”的F-1杂种表现出与HWA1和HWA2位点有关的杂交弱点。因此，本研究的目的是分析“P.T.B.7”与“A.D.T.14”杂交种的杂种弱表型。杂种F-1的株高和分蘖数均低于亲本，且表现出亲本均未出现的叶片泛黄现象。此外，本研究还表明，与叶绿素含量相关的SPAD值可以准确反映叶片黄化程度，因此可以有效评估与HWA1和HWA2位点相关的杂交弱化进展。在F-1杂交种变黄的叶片中检测到细胞死亡和活性氧H2O2。此外，抗病相关基因在F-1杂交种的黄化叶片中表达上调，而光合作用相关基因则趋于下调。这些结果表明，与HWA1和HWA2位点相关的杂交弱点涉及超敏反应样机制。
Hybrid weakness is a type of reproductive isolation in which F-1 hybrids of normal parents exhibit weaker growth characteristics than their parents. F-1 hybrid of the Oryza sativa Indian cultivars 'P.T.B.7' and 'A.D.T.14' exhibits hybrid weakness that is associated with the HWA1 and HWA2 loci. Accordingly, the aim of the present study was to analyze the hybrid weakness phenotype of the 'P.T.B.7' x 'A.D.T.14' hybrids. The height and tiller number of the F-1 hybrid were lower than those of either parent, and F-1 hybrid also exhibited leaf yellowing that was not observed in either parent. In addition, the present study demonstrates that SPAD values, an index correlated with chlorophyll content, are effective for evaluating the progression of hybrid weakness that is associated with the HWA1 and HWA2 loci because it accurately reflects degree of leaf yellowing. Both cell death and H2O2, a reactive oxygen species, were detected in the yellowing leaves of the F-1 hybrid. Furthermore, disease resistance-related genes were upregulated in the yellowing leaves of the F-1 hybrids, whereas photosynthesis-related genes tended to be downregulated. These results suggest that the hybrid weakness associated with the HWA1 and HWA2 loci involves hypersensitive response-like mechanisms.