Pandey Shiv S, Singh Sucheta, Babu C S Vivek, Shanker Karuna, Srivastava N K, Kalra Alok
Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India.
CSIR-Central Institute of Medicinal and Aromatic Plants, Research Centre, Allalasandra, GKVK Post, Bangalore, 560065, India.
Planta. 2016 May;243(5):1097-114. doi: 10.1007/s00425-016-2467-9. Epub 2016 Jan 21.
Endophytes reside in different parts of the poppy plant and perform the tissue-specific functions. Most leaf endophytes modulate photosynthetic efficiency, plant growth, and productivity while capsule endophytes modulate alkaloid biosynthesis. Endophytes promote plant growth, provide protection from environmental stresses and are the source of important secondary metabolites. Here, we established that the endophytes of opium poppy Papaver somniferum L. may play a role in the modulation of plant productivity and benzylisoquinoline alkaloid (BIA) biosynthesis. A total of 22 endophytes isolated from leaves, roots, capsules and seeds of the poppy plants were identified. Isolated endophytes were used to inoculate the endophytes free poppy seeds and screened for their ability to improve plant productivity and BIA production. It was evident that the endophytes from leaf were involved in improving photosynthetic efficiency, and thus crop growth and yield and the endophytes from capsule were involved in enhancing BIA biosynthesis. Capsule endophytes of alkaloid-rich P. somniferum cv. Sampada enhanced BIA production even in alkaloid-less cv. Sujata. Expression study of the genes involved in BIA biosynthesis conferred the differential regulation of their expression in the presence of capsule endophytes. The capsule endophyte SM1B (Acinetobacter) upregulated the expression of the key genes for the BIA biosynthesis except thebaine 6-O-demethylase (T6ODM) and codeine O-demethylase (CODM). On the other hand, another capsule endophyte SM3B (Marmoricola sp.) could upregulate both T6ODM and CODM. Colonization of poppy plant by endophytes isolated from leaves, roots and capsules found to be higher in their respective plant parts confirmed their tissue-specific role. Overall, the results demonstrate the specific role of endophytes in the modulation of host plant productivity and BIA production.
内生菌存在于罂粟植物的不同部位并执行组织特异性功能。大多数叶片内生菌调节光合效率、植物生长和生产力,而蒴果内生菌调节生物碱生物合成。内生菌促进植物生长,提供对环境胁迫的保护,并且是重要次生代谢产物的来源。在此,我们确定罂粟 Papaver somniferum L. 的内生菌可能在调节植物生产力和苄基异喹啉生物碱(BIA)生物合成中发挥作用。从罂粟植物的叶、根、蒴果和种子中分离出总共22种内生菌。分离出的内生菌用于接种无菌罂粟种子,并筛选它们提高植物生产力和BIA产量的能力。很明显,来自叶片的内生菌参与提高光合效率,从而促进作物生长和产量,而来自蒴果的内生菌参与增强BIA生物合成。富含生物碱的罂粟品种Sampada的蒴果内生菌即使在生物碱含量低的品种Sujata中也能提高BIA产量。对参与BIA生物合成的基因的表达研究表明,在存在蒴果内生菌的情况下它们的表达存在差异调节。蒴果内生菌SM1B(不动杆菌属)上调了除蒂巴因6-O-脱甲基酶(T6ODM)和可待因O-脱甲基酶(CODM)之外的BIA生物合成关键基因的表达。另一方面,另一种蒴果内生菌SM3B(Marmoricola sp.)可以上调T6ODM和CODM。从叶、根和蒴果分离出的内生菌在罂粟植物中的定殖在其各自的植物部位更高,这证实了它们的组织特异性作用。总体而言,结果证明了内生菌在调节宿主植物生产力和BIA产量方面的特定作用。