Involvement of facultative apomixis in inheritance of EPSPS gene amplification in glyphosate-resistant Amaranthus palmeri
Involvement of facultative apomixis in inheritance of EPSPS gene amplification in glyphosate-resistant Amaranthus palmeri
复制标题
DOI：
10.1007/s00425-013-1972-3
复制
发表时间：
2014-01-01
期刊：
影响因子：
4.3
通讯作者：
Dayan, Franck E.
中科院分区：
文献类型：
--
作者：
Ribeiro, Daniela N.;Pan, Zhiqiang;Dayan, Franck E.
通过抗草甘膦（R）和感草甘膦（S）亲本间的正反交（RC）和二次正反交（2 RC）研究了长穗苋（Amaranthuspalmeri）两个群体（R1和R2）的草甘膦抗性遗传。R群体和Female-R x Male-S杂交包含比S群体更高的5-烯醇式莽草酸-3-磷酸合酶（EPSPS）基因拷贝数。EPSPS表达量、酶活性、蛋白质含量和草甘膦抗性水平与基因组EPSPS相对拷贝数呈正相关。尽管EPSPS基因在核基因组中有多拷贝扩增，但母本对抗性传递的影响大于父本。这使我们推测，这种令人困惑的遗传模式可能是由A. palmeri。我们证实了生殖隔离的R和S雌性植株产生种子，表明A。palmeri可以有性和无融合生殖（兼性无融合生殖）产生种子。这种无融合生殖性状解释了雌性-S X雄性-R后代中的低拷贝数遗传。无融合生殖也可能提高草甘膦抗性性状的稳定性在R种群中的生殖伴侣的情况下。
The inheritance of glyphosate resistance in two Amaranthus palmeri populations (R1 and R2) was examined in reciprocal crosses (RC) and second reciprocal crosses (2RC) between glyphosate-resistant (R) and -susceptible (S) parents of this dioecious species. R populations and Female-R x Male-S crosses contain higher 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene copy numbers than the S population. EPSPS expression, EPSPS enzyme activity, EPSPS protein quantity, and level of resistance to glyphosate correlated positively with genomic EPSPS relative copy number. Transfer of resistance was more influenced by the female than the male parent in spite of the fact that the multiple copies of EPSPS are amplified in the nuclear genome. This led us to hypothesize that this perplexing pattern of inheritance may result from apomictic seed production in A. palmeri. We confirmed that reproductively isolated R and S female plants produced seeds, indicating that A. palmeri can produce seeds both sexually and apomictically (facultative apomixis). This apomictic trait accounts for the low copy number inheritance in the Female-S x Male-R offsprings. Apomixis may also enhance the stability of the glyphosate resistance trait in the R populations in the absence of reproductive partners.