摘要
水稻穗部是影响产量的重要农艺性状,其发育健全与否直接决定了水稻产量的高低.过去几十年已经有大量的粒型和穗粒数相关基因被克隆报道,但调控穗顶发育相关基因的克隆与功能的报道较少.本研究通过甲基磺酸乙酯(EMS)诱变籼稻品种宜香1B,筛选到一个能稳定遗传的穗顶退化突变体材料paa1331(panicleapical abortion1331).与野生型相比,该突变体主要表现为穗顶端严重退化(退化率高达53%),株高变矮,分蘖减少,穗粒数降低.台盼蓝染色结果表明,穗顶端退化伴随细胞程序性死亡;激素测定结果证明,突变体穗顶部生长素含量高于野生型.遗传分析表明,该突变性状受隐性单基因控制;通过图位克隆与重测序分析发现,基因LOC_Os04g40720第4外显子的碱基A突变成G,导致编码的氨基酸由天冬酰胺变为天冬氨酸.目前该基因未见报道,暂将该基因定为候选基因.
Rice panicle is an important agronomic organ which influences yield,and its development directly determines the yield potential.Over the past decades,a large number of genes related to grain size and grain number have been cloned,but there are few reports on cloning and function characterization of genes related to panicle development.We aim to explore the genes that regulate the degeneration of rice spike,improve the regulation network of panicle development,and provide theoretical basis for molecular breeding.In this study,a stably inherited mutant showing perturbed development of panicle(panicle apical abortion 1331)was isolated from an ethyl methyl sulfate(EMS)mutagenized population of Yixiang 1B.Compared with the wild type,the mutant mainly showed a severe degeneration at the panicle tip(the affected florets account for as high as 53%),in addition to this,the plant height,tiller number and grain number were also affected.Observation on the development of panicle showed that the top spikelets of mutant paa1331 began to degrade during meiosis of the pollen mother cell,and the number of degenerated spikelets increased with the elongation of the young spike,distributing at the top of the first branch of the stem,while the number of degenerated spikelets showed a tendency to decrease gradually from top to bottom.Anatomical observations showed that the stamens of the mutant degenerated spikelets degenerated into linear,and the pulp was withered.The tissue section of mutant paa1331 and pollen staining assay showed that there were no pollen grains in the mutant anther,indicating that degeneration hindered the development of pollen;the vascular bundle of the mutant degenerated stem showed developmental defects,which may cause the transport of the material to be obstructed Trypan blue staining assay showed severe coloration of degraded spikelets on top of mutants,indicted that the panicle apical abortion was associated with programmed cell death.Hormone assay suggested that the IAA content of mutants was higher than that of wild type.Genetic analysis showed that mutant trait was controlled by a recessive gene.Combined the analysis of map-based cloning and De novo genome sequencing,we found one gene LOC_Os04g40720,of which the fourth exon has an A-to-G single base substitution,which resulted in a change from Asn to Asp.At present,this gene has not been reported to confer function in panicle development,thus we treated it as candidate gene.
作者
侯飞雪
彭永彬
韩小行
白鹊
顾朝剑
孙朝伟
何曜
张红宇
Feixue Hou;Yongbin Peng;Xiaohang Han;Que Bai;Chaojian Gu;Chaowei Sun;Yao He;Hongyu Zhang(Key Laboratory of Crop Genetic Resources and Genetic Improvement,Ministry of Education,Institute of Rice Research,Sichuan Agricultural University,Chengdu 611130,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2018年第31期3192-3203,共12页
Chinese Science Bulletin
基金
四川省科技厅项目(2016HH0044)
四川省农作物育种公关项目资助
