ORIGINAL PAPER Association with arbuscular mycorrhizal fungi inﬂuences alkaloid synthesis and accumulation in Catharanthus roseus and Nicotiana tabacum plants S. A. L. Andrade • S. Malik • A. C. H. F. Sawaya • A. Bottcher • P. Mazzafera Received: 27 June 2012 / Revised: 15 October 2012 / Accepted: 17 October 2012 / Published online: 31 October 2012 Ó Franciszek Go´rski Institute of Plant Physiology, Polish Academy of Sciences, Krako´w 2012 Abstract Frequently disregarded, plant associations with arbuscular mycorrhizal fungi (AMF) can inﬂuence plant specialized metabolism with important ecological and/or economic implications. In this study, we report on both the inﬂuence of mycorrhization on the content of a wide range of alkaloids and differential gene expression of some enzymes involved in alkaloid biosynthetic pathways in the leaves and roots of Catharanthus roseus and Nicotiana tabacum plants. These plants were divided into several treatments: mycorrhizal, inoculated with AMF; non-AMF inoculated plants; and non-AMF inoculated plants with an extra supply of phosphorus. The contents of vindoline, vinblastine, vincristine, catharanthine, ajmalicine and serpentine in C. roseus and of nicotine, anabasine and nornicotine in N. tabacum tobacco plants were determined. Mycorrhizal inoculation increased ajmalicine and serpen- tine contents in C. roseus roots suggesting that mycorrh- ization had a greater inﬂuence on the accumulation of alkaloids in roots than it did in shoots. The youngest leaves of mycorrhizal C. roseus plants showed lower transcript levels of the genes analysed; however, in older leaves, the expression levels were higher when compared with the leaves of non-mycorrhizal plants. In the case of tobacco, higher leaf to root ratios for nicotine and anabasine were found in plants with a mycorrhizal association. Our results showed that mycorrhization changed the alkaloid content and expression pattern of the genes analysed in both spe- cies; however, differences were found between the roots and shoots. In nature, such changes may have a direct inﬂuence on the interactions between plants and insects (herbivory) and pathogens. These interactions must be studied further to reveal the ecological inﬂuence mycor- rhizae may have on chemical defences in a broader sense. Keywords Mycorrhizae  Specialized metabolites  Catharanthus  Nicotiana Introduction Arbuscular mycorrhizal fungi (AMF) are ubiquitous in soils. AMF belong to a group of beneﬁcial microorganisms that can mutualistically associate with the roots of the vast majority of terrestrial plants (Smith and Read 2008). The inﬂuence of arbuscular mycorrhizae (AM) on plant spe- cialized metabolite accumulation and biosynthesis is still understudied (Toussaint 2007; Vannette and Hunter 2009), although quantitative and qualitative changes in several classes of plant specialized metabolites have been attrib- uted to mycorrhization (Abu-Zeyad et al. 1999; Kapoor et al. 2007; Zubek et al. 2011). These alterations have frequently been connected with the higher biomass yields of mycorrhizal plants and are usually linked to the nutritional beneﬁts of mycorrhization (Liu et al. 2007; Zubek et al. 2010). The expression of different genes related to the plant defence system is directly inﬂuenced by AM, with conse- quences for whole-plant ﬁtness and its response to biotic stressors (Pozo and Azco´n-Aguilar 2007). In this way, it is Communicated by M. H. Walter. Electronic supplementary material The online version of this article (doi:10.1007/s11738-012-1130-8) contains supplementary material, which is available to authorized users. S. A. L. Andrade (&)  S. Malik  A. C. H. F. Sawaya  A. Bottcher  P. Mazzafera Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, 13083-970 Campinas, Sa˜o Paulo, Brazil e-mail: sara.adrian@gmail.com; sardrian@unicamp.br 123 Acta Physiol Plant (2013) 35:867–880 DOI 10.1007/s11738-012-1130-8