A Novel Chimeric Mitochondrial Gene Confers Cytoplasmic Effects on Seed Oil Content in Polyploid Rapeseed (Brassica napus)
A Novel Chimeric Mitochondrial Gene Confers Cytoplasmic Effects on Seed Oil Content in Polyploid Rapeseed (Brassica napus)
复制标题
一种新型嵌合线粒体基因对多倍体油菜籽油含量产生细胞质影响
DOI：
10.1016/j.molp.2019.01.012
复制
发表时间：
2019-04-01
期刊：
影响因子：
27.5
通讯作者：
Wang, Hanzhong
中科院分区：
文献类型：
--
作者：
Liu, Jun;Hao, Wanjun;Wang, Hanzhong
细胞质效应（CE）已被发现影响作物的各种农艺性状，了解其潜在机制有助于加速育种计划。种子含油量（SOC）具有重要的农业、营养和经济意义。然而，在SOC（CE-SOC）上的CEs的遗传基础仍然是谜。本研究采用优化的方法对异源四倍体油菜（Brassica napus）品种51218和56366的细胞质（质体和线粒体）基因组进行了测序，并结合比较基因组学和全基因组转录组分析，确定了Orf 188基因可能是一个CE-SOC决定基因。在模式系统拟南芥和油菜中的功能分析表明，orf 188控制CE-SOC，并能显著提高SOC，通过促进ATP的产量。与这一发现相一致，微阵列和RNA测序的转录谱显示orf 188影响线粒体的转录重编程！能量代谢促进ATP的产生。orf 188是一个尚未被鉴定的嵌合基因，该新奇的存在赋予了油菜正CE-SOC，揭示了多倍体作物关键数量性状CEs的分子基础，丰富了含油量的母体控制理论，为高油油菜育种提供了新的科学指导。
Cytoplasmic effects (CEs) have been discovered to influence a diverse array of agronomic traits in crops, and understanding the underlying mechanisms can help accelerate breeding programs. Seed oil content (SOC) is of great agricultural, nutritional, and economic importance. However, the genetic basis of CEs on SOC (CE-SOC) remains enigmatic. In this study, we use an optimized approach to sequence the cytoplasmic (plastid and mitochondrial) genomes of allotetraploid oilseed rape (Brassica napus) cultivars, 51218 and 56366, that bear contrasting CE-SOC. By combining comparative genomics and genome-wide transcriptome analysis, we identify mitochondria-encoded orf188 as a potential CE-SOC determinant gene. Functional analyses in the model system Arabidopsis thaliana and rapeseed demonstrated that orf188 governs CE-SOC and could significantly increase SOC, strikingly, through promoting the yield of ATP. Consistent with this finding, transcriptional profiling with microarray and RNA sequencing revealed that orf188 affects transcriptional reprogramming of mitochondria! energy metabolism to facilitate ATP production. Intriguingly, orf188 is a previously uncharacterized chimeric gene, and the presence of this genetic novelty endows rapeseed with positive CE-SOC. Our results shed light on the molecular basis of CEs on a key quantitative trait in polyploid crops and enrich the theory of maternal control of oil content, providing new scientific guidance for breeding high-oil rapeseed germplasms.