Biologie von Mitrastemon Yamamotoi MAKINO (Rafflesiaceae)

Striking developmental convergence in angiosperm endoparasites

“…5C), as described by Nikolov et al (2014a). Simultaneously, endophytic tissue also reaches the host xylem via wood rays, as observed by previous authors (Brown, 1912; Watanabe, 1934; Dell et al, 1982; Forstmeier et al, 1983). Once in contact with host vessels, endoparasitic parenchyma cells then differentiate into tracheary elements, forming a direct xylem bridge between parasite and host (Fig.…”

“…Still, it is noteworthy that the developmental pattern described here for Bdallophytum americanum closely corresponds to what has been described for its sister genus, Cytinus (De Vega et al, 2007). The same can be said about Mitrastemon matudae and its sister species, M. yamamotoi (Jochems, 1928; Watanabe, 1933, 1934). Studies addressing the development of Apodanthes caseariae appear to be lacking in the literature.…”

“…Likewise, host xylem penetration was not detected in portions of the endophyte not directly associated with bud formation. The development of endoparasitic tissue has often been described to disrupt the host bark and the organization of the host secondary phloem and xylem (Unger, 1840; Brown, 1912; Watanabe, 1934; Dell et al, 1982; Forstmeier et al, 1983). We also observed conspicuous host vessel re‐orientation, i.e., newly formed host vessel elements being differentiated toward parasitic tissues, as would be observed in branching stems/roots.…”

Neglected plant parasites: Mitrastemonaceae

“…In infested hosts, high vessel density and reduced vessel lumen size is apparent, especially in the area promoting an intersection between the parasite flower buds and the host wood (Teixeira‐Costa et al, 2021). An increase in vessel proliferation could then induce the initiation of multiple lateral roots (Aloni, 2021), leading to a bifurcated branching pattern with roots that run closer to soil surface (Suetsugu & Yamashita, in press; Watanabe, 1933b, 1934a). In other host–parasite systems, structural modifications have been related to changes in host cambial activity promoted by the parasite (Aloni, 2015; Spallek et al, 2017; Teixeira‐Costa & Ceccantini, 2015), which appears to be a common feature of host–parasite interactions (Teixeira‐Costa, 2021).…”

“…and a bird species ( Zosterops sp.) have been occasionally reported to forage for nectar among M. yamamotoi flowers (Matuda, 1947; Watanabe, 1934a). It was only recently that Suetsugu (2019) unequivocally showed that hornets (Figure 3d), crickets (Figure 3e), and cockroaches (Figure 3f) effectively pollinate Mitrastemon .…”