Endophytic bacteria in Miscanthus seed: implications for germination, vertical inheritance of endophytes, plant evolution and breeding
Endophytic bacteria in Miscanthus seed: implications for germination, vertical inheritance of endophytes, plant evolution and breeding
复制标题
DOI：
10.1111/gcbb.12364
复制
发表时间：
2017-01-01
影响因子：
5.6
通讯作者：
Farrar, Kerrie
中科院分区：
文献类型：
--
作者：
Cope-Selby, Naomi;Cookson, Alan;Farrar, Kerrie
随着人们对微生物组，特别是共生体的作用越来越感兴趣，本研究的目的是确定芒草内细菌内生菌种群的多样性，并确定通过种子垂直传播的程度。在成熟植物的所有部分（根茎、根、茎和叶）以及在无菌条件下生长的灭菌种子生长的幼苗中发现了大量多样性的内生细菌。使用16S rDNA扩增和测序，与19个门和85个家族相比，共鉴定出3个门和5个家族的细菌作为培养物。并非所有培养的细菌都可以通过16S rDNA鉴定，这意味着真正的多样性甚至更大。更多的细菌多样性被确定在不育生长的幼苗比在所有部分的成熟植物相结合，17和13门，分别有11个共同的。五门存在于所有植物样品检查。因此，通过种子的垂直传播可能是芒属植物内生菌的主要来源，可能是植物生长时土壤细菌进入的补充。从成熟植物中鉴定出的细菌主要与GenBank中已知的细菌序列相似，但少量来自茎和许多来自种子的细菌是新的，可能适应于植物体内的生命周期。内生细菌被发现形成孢子和其他致密结构，这为长期存活和种子传播提供了机制。发芽种子的染色鉴定出在出现的胚根的根尖处的细菌。我们建议，种子传播的细菌内生菌需要适应植物和微生物，在发芽中发挥作用，并具有进化意义和影响未来的植物育种方法，在芒草和更广泛。
With growing interest in the role of microbiomes, and symbionts in particular, the aim of this study was to determine the diversity of the bacterial endophyte population within Miscanthus and to ascertain the extent of vertical transmission via the seed. A great diversity of endophytic bacteria was found in all parts of the mature plant (rhizome, root, stem and leaf), and in seedlings grown from sterilized seed grown in sterile conditions. A total of three phyla and five families of bacteria were identified as cultures compared to 19 phyla and 85 families using 16S rDNA amplification and sequencing. Not all cultured bacteria could be identified by 16S rDNA, implying that the true diversity is even greater. More bacterial diversity was identified in sterile-grown seedlings than in all parts of the mature plant combined, 17 and 13 phyla, respectively, with 11 in common. Five phyla were present in all plant samples examined. Vertical transmission via the seed may therefore be a major source of endophytes in Miscanthus, presumably supplemented by ingress of soil bacteria as the plant grows. Bacteria identified from the mature plant were predominantly similar to known bacterial sequences in GenBank, but a small number from the stem and many from the seed were novel, potentially adapted to an in planta life cycle. Endophytic bacteria were found to form spores and other dense structures, and this provides a mechanism for long-term survival and seed transmission. The staining of germinating seeds identified bacteria at the root tip of the emerging radicle. We propose that seed transmission of bacterial endophytes requires adaptation of both plant and microbes, plays a role in germination and has evolutionary significance and implications for future plant breeding approaches, in Miscanthus and more widely.