Data from: Suppression of reproductive characteristics of the invasive plant Mikania micrantha by sweet potato competition

Background: As a means of biologically controlling Mikania micrantha H.B.K. in Yunnan, China, the influence of sweet potato [Ipomoea batatas (L.) Lam.] on its reproductive characteristics was studied. The trial utilized a de Wit replacement series incorporating six ratios of sweet potato and M. micrantha plants in 25 m2 plots over two years. Results: Budding of M. micrantha occurred at the end of September; flowering and fruiting occurred from October to February. Flowering phenology of M. micrantha was delayed (P<0.05), duration of flowering and fruiting was reduced (P<0.05) and duration of bud formation was increased (P<0.05) with increasing proportions of sweet potato. Reproductive allocation, reproductive investment and reproductive index of M. micrantha were significantly reduced (P<0.05) with increasing sweet potato densities. Apidae bees, and Calliphoridae or Syrphidae flies were the most abundant visitors to M. micrantha flowers. Overall flower visits decreased (P<0.05) as sweet potato increased. Thus the mechanism by which sweet potato suppressed sexual reproduction in M. micrantha was essentially two-fold: causing a delay in flowering phenology and reducing pollinator visits. The number, biomass, length, set rate, germination rate, and 1000-grain dry weight of M. micrantha seeds were suppressed (P<0.05) by sweet potato competition. With proportional increases in sweet potato, sexual and asexual seedling populations of M. micrantha were significantly reduced (P<0.05). The mortality of both seedling types increased (P<0.05) with proportional increases in sweet potato. Conclusions: These results suggest that sweet potato significantly suppresses the reproductive ability of the invasive species M. micrantha, and is a promising alternative to traditional biological control and other methods of control. Planting sweet potato in conjunction with other control methods could provide a comprehensive strategy for managing M. micrantha. The scenario of controlling M. micrantha by utilizing a crop with a similar growth form may provide a useful model for similar management strategies in other systems

Biology and Impacts of Pacific Islands Invasive Species. 13. Mikania micrantha Kunth (Asteraceae)

Abstract: Mikania micrantha Kunth, commonly known as bitter vine, American rope, or mile-a-minute, is a rapidly growing vine, native to tropical America. Mikania micrantha is present in 20 Pacific island countries and territories, including Australia, the Cook Islands, Fiji, French Polynesia, Micronesia, Papua New Guinea, Samoa, Solomon Islands, and Vanuatu. A CLIMEX model based on native distribution of M. micrantha suggests that most of the islands in the Pacific, southern Asia, and parts of southern and central Africa are climatically suitable for M. micrantha, leaving these areas vulnerable to new or further incursions. Its rapid spread is a threat to both natural and agricultural environments, where it kills or reduces growth of preferred species, severely impacting on biodiversity and production. Large numbers of wind-dispersed seeds and ability to propagate vegetatively from stem fragments facilitate rapid invasion. Management of M. micrantha is difficult. Several postemergence herbicides exhibit some efficacy, but manual control via hand pulling and slashing is more commonly practiced. However, slashing may result in increased growth from fragments, and plants may regenerate from roots after herbicide application. Cultural techniques such as fallowing or burning may also help limit spread. Competitors that produce ample vegetation such as sweet potato (Ipomoea batatas [L.] Lam.) may be effective for suppression in some situations. Various studies have shown that Mikania micrantha exhibits some genetic diversity across biotypes encountered in southern Asia. Although little is currently known about its population genetics across the South Pacific, more information will undoubtedly facilitate potential for future biological control. A rust pathogen, Puccinia spegazzinii, introduced from South America was established in Taiwan in 2008, in Papua New Guinea and Fiji in 2009, and in Vanuatu in 2012 for biological control. The dodder Cuscuta campestris Yuncker has also shown some efficacy against M. micrantha, but its status as a known pest limits its use as a biological control agent. Recent research into the mikania wilt virus as a biocontrol agent is in its infancy, and it is too early to recommend it to assist with the management of M. micrantha. Given the difficulty of controlling M. micrantha once established and the early stages of research into biological control, high priority must be given to preventing colonization of Pacific islands where M. micrantha is not yet present, through early detection and rapid response to new incursions

Data for suppression of reproductive characteristics of Mikania micrantha by sweet potato competition

Data for the following parameters for Mikania micrantha in experiments when grown with sweet potato in different ratios (each set of parameters on a separate tab on the excel file): flowering phenology, pollinators, flowering characteristics, seeds, populatio

Polyketide decarboxylative chain termination preceded by O-sulfonation in curacin A biosynthesis

(Figure Presented) Biosynthetic innovation in natural product systems is driven by the recruitment of new genes and enzymes into these complex pathways. Here, an unprecedented decarboxylative chain termination mechanism is described for the polyketide synthase of curacin A, an anticancer lead compound isolated from the marine cyanobacterium Lyngbya majuscula. The unusual chain termination module containing adjacent sulfotransferase (ST) and thioesterase (TE) catalytic domains embedded in CurM was biochemically characterized. The TE was proved to catalyze a hydrolytic chain release of the polyketide chain elongation intermediate. Moreover, a selective ST-mediated sulfonation of the (R)-β-hydroxyl group was found to precede TE-mediated hydrolysis, triggering a successive decarboxylative elimination and resulting in the formation of a rare terminal olefin in the final metabolite. Copyright © 2009 American Chemical Society

Fatty Acid-Related Phylogeny of Myxobacteria as an Approach to Discover Polyunsaturated Omega-3/6 Fatty Acids ▿ †

In an analysis of 47 aerobic myxobacterial strains, representing 19 genera in suborders Cystobacterineae, Nannocystineae, Sorangiineae, and a novel isolate, “Aetherobacter” SBSr008, an enormously diverse array of fatty acids (FAs) was found. The distribution of straight-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs) supports the reported clustering of strains in the phylogenetic tree based on 16S rRNA genes. This finding additionally allows the prediction and assignment of the novel isolate SBSr008 into its corresponding taxon. Sorangiineae predominantly contains larger amounts of SCFA (57 to 84%) than BCFA. On the other hand, Cystobacterineae exhibit significant BCFA content (53 to 90%), with the exception of the genus Stigmatella. In Nannocystineae, the ratio of BCFA and SCFA seems dependent on the taxonomic clade. Myxobacteria could also be identified and classified by using their specific and predominant FAs as biomarkers. Nannocystineae is remarkably unique among the suborders for its absence of hydroxy FAs. After the identification of arachidonic (AA) FA in Phaselicystidaceae, eight additional polyunsaturated fatty acids (PUFAs) belonging to the omega-6 and omega-3 families were discovered. Here we present a comprehensive report of FAs found in aerobic myxobacteria. Gliding bacteria belonging to Flexibacter and Herpetosiphon were chosen for comparative analysis to determine their FA profiles in relation to the myxobacteria