调控水稻异倍性杂交种子败育的相关基因分析  

Analysis of genes regulating seed abortion in heteroploid crosses of rice

作　　者：吴丽梅[1] 朱晓炜[1,2] 崔晓云[1] 刘志坚[1] 刘禹彤[1] 徐培洲[1] 陈晓琼[1] 吴先军[1] 张红宇[1] 

机构地区：[1]四川农业大学水稻研究所西南作物基因资源与遗传改良教育部重点实验室长江流域杂交水稻协同创新中心,成都611130 [2]中国科学院遗传与发育生物学研究所,北京100101

出　　处：《科学通报》2015年第17期1592-1601,共10页Chinese Science Bulletin

基　　金：国家自然科学基金(31301049);农业部公益性行业科研专项(201403002-3);四川省国际科技合作项目(2013HH0023);四川省教育厅项目(12ZA123)资助

摘　　要：MADS29是控制水稻(Oryza sativa L.)种子饱满程度的基因,它通过调控母体组织细胞退化和维持体内激素平衡来影响种子发育.水稻异倍性杂交往往产生败育种子,为了探讨MADS29等种子发育相关基因是否参与其调控,本研究以4份水稻材料(2个二倍体;2个四倍体)构建4个自交组合(对照)和8个杂交组合(正反交),对花粉粒育性、花粉管萌发及伸长、种子发育及MADS29等相关基因表达进行分析.结果表明:(1)异倍性杂交均可正常受精,但杂交种子败育;(2)石蜡切片结果显示,授粉后3 d(3 day after pollination,3 DAP),与对照相比,4n×2n胚乳已进入细胞化时期,但细胞数量较少;而2n×4n胚乳处于合胞体时期,游离核周围未形成细胞壁,胚乳细胞化时期滞后;(3)实时荧光定量PCR(q RT-PCR)表明,6 DAP和8 DAP,MADS29、生长素基因和母体组织细胞程序化死亡(PCD)相关基因的相对表达量在杂交种子中均明显高于对照;淀粉合成基因在杂交种子中的相对表达量显著低于对照.本实验结果表明,在水稻异倍性杂交中,MADS29高表达,生长素基因和母体组织PCD相关基因表达上调,淀粉合成相关基因表达下调,导致胚乳发育异常、种子败育,说明MADS29的高表达导致异倍性杂交种子败育,是一种有别于二倍体水稻种子发育的新型调控方式.The MADS29 gene regulates the plumpness of rice seeds and affects seed development by regulating the degradation of maternal tissues and maintaining the plant’s hormone balance. Rice seeds produced by heteroploid crosses exhibit greater rate of sterility than that by seeds of other plants. To determine whether MADS29 and its related genes regulate seed development, we used four rice cultivars（two diploid and two tetraploid） to produce four self-crossed combinations as the control and eight hybridized combinations as reciprocal crosses. Then, pollen grain fertility, pollen germination, and seed development were observed, and the expressions of MADS29 and related genes were quantified using RT-PCR. The results showed the following：（1） heteroploid crosses showed 100% successful fertilization, with non-negligible rate of seed abortion.（2） Based on examinations of paraffin sections of seeds at 3 days after pollination（3 DAP） in a 4n×2n cross, the endosperm had entered the cellularization stage, but the number of cells was lower than that in the control. However, in the endosperm of seeds of 2n×4n crosses, the cell walls did not form around the nucleus. In addition, some vacuolation was noted in the endosperm, and cellularization was delayed.（3） q RT-PCR results showed that the relative expression levels of MADS29, IAA, and programmed cell death（PCD） genes associated with maternal tissues in hybrid seeds at 6 DAP and 8 DAP were significantly higher than those of the control. On the contrary, the relative expression of starch synthesis genes in hybrid seeds was significantly lower than that of the control. This suggests that MADS29 is more highly expressed in the seeds of heteroploid crosses. In addition, it suggested that the expressions of IAA and other genes involved in the PCD of maternal tissues was upregulated in the same seeds. However, starch synthesis genes showed downregulated expression levels, leading to the abnormal development of the endosperm, followed by seed abortion. Thus,

关 键 词：MADS29 水稻 异倍性杂交 种子败育 

分 类 号：S511[农业科学—作物学]