scholarly journals Pyrrolizidine alkaloid variation in Senecio vulgaris populations from native and invasive ranges

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3686 ◽  
Author(s):  
Dandan Cheng ◽  
Viet-Thang Nguyen ◽  
Noel Ndihokubwayo ◽  
Jiwen Ge ◽  
Patrick P.J. Mulder

Biological invasion is regarded as one of the greatest environmental problems facilitated by globalization. Some hypotheses about the invasive mechanisms of alien invasive plants consider the plant–herbivore interaction and the role of plant defense in this interaction. For example, the “Shift Defense Hypothesis” (SDH) argues that introduced plants evolve higher levels of qualitative defense chemicals and decreased levels of quantitative defense, as they are released of the selective pressures from specialist herbivores but still face attack from generalists. Common groundsel (Senecio vulgaris), originating from Europe, is a cosmopolitan invasive plant in temperate regions. As in other Senecio species, S. vulgaris contains pyrrolizidine alkaloids (PAs) as characteristic qualitative defense compounds. In this study, S. vulgaris plants originating from native and invasive ranges (Europe and China, respectively) were grown under identical conditions and harvested upon flowering. PA composition and concentration in shoot and root samples were determined using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). We investigated the differences between native and invasive S. vulgaris populations with regard to quantitative and qualitative variation of PAs. We identified 20 PAs, among which senecionine, senecionine N-oxide, integerrimine N-oxide and seneciphylline N-oxide were dominant in the roots. In the shoots, in addition to the 4 PAs dominant in roots, retrorsine N-oxide, spartioidine N-oxide and 2 non-identified PAs were also prevalent. The roots possessed a lower PA diversity but a higher total PA concentration than the shoots. Most individual PAs as well as the total PA concentration were strongly positively correlated between the roots and shoots. Both native and invasive S. vulgaris populations shared the pattern described above. However, there was a slight trend indicating lower PA diversity and lower total PA concentration in invasive S. vulgaris populations than native populations, which is not consistent with the prediction of SDH.

2015 ◽  
Vol 282 (1805) ◽  
pp. 20141351 ◽  
Author(s):  
Jarad P. Mellard ◽  
Claire de Mazancourt ◽  
Michel Loreau

According to recent reviews, the question of how trophic interactions may affect evolutionary responses to climate change remains unanswered. In this modelling study, we explore the evolutionary dynamics of thermal and plant–herbivore interaction traits in a warming environment. We find the herbivore usually reduces adaptation speed and persistence time of the plant by reducing biomass. However, if the plant interaction trait and thermal trait are correlated, herbivores can create different coevolutionary attractors. One attractor has a warmer plant thermal optimum, and the other a colder one compared with the environment. A warmer plant thermal strategy is given a head start under warming, the only case where herbivores can increase plant persistence under warming. Persistence time of the plant under warming is maximal at small or large thermal niche width. This study shows that considering trophic interactions is necessary and feasible for understanding how ecosystems respond to climate change.


Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 562-562 ◽  
Author(s):  
S. T. Koike ◽  
M. Scholler ◽  
Arthur Herbaria ◽  
Kriebel Herbaria

English daisy (Bellis perennis, family Asteraceae) is a flowering plant native to Europe. It is widely used as an ornamental in North America but is also a weed in lawns in the western and eastern United States. In December 2000, plants growing in urban landscapes in Monterey County, CA, were infected with rust. Orange aecia containing aeciospores that measured 14 to 18 × 12.5 to 15 μm developed profusely on leaves. Severely diseased leaves wilted and collapsed. Other spore states (pycnia, uredosori, and telia) were not observed. Based on the size and ornamentation of the aeciospores, reduced white peridium, apperance of the peridial cells, and arrangement of sori, we identified the pathogen as Puccinia lagenophorae Cooke (1,3), a rust fungus native to Australia and New Zealand that since 1960 has been introduced to other continents (2). On English daisy, the disease has been reported only in Australia and Europe (1). The pathogen also occurs on numerous other plants of the subfamily Asteroideae (family Asteraceae) (2). The occurrence of P. lagenophorae on English daisy follows the recent, first-time detection of the same pathogen on common groundsel (Senecio vulgaris) in California (3). To test cross infectivity, a spore suspension of a rust isolate from common groundsel was prepared and applied to various ornamental plants known to be hosts of P. lagenophorae. Inoculated plants were kept in a humidity chamber for 48 h, then maintained in a greenhouse. After 9 to 14 days, aecia developed on English daisy, cineraria (S. cruentus), and common groundsel but did not develop on dusty miller (S. cineraria) or pot marigold (Calendula officinalis). In addition, a single telium, surrounded by aecia, was observed on one of the infected English daisy plants. The telium contained two-celled teliospores that measured 31 to 36.5 × 16 to 19 (-22) μm and one-celled mesospores that measured 22 to 34 × 13.5 to 16 μm. At point of attachment, the widths of the stalks measured 7 to 8.5 (-9.5) μm. Some of the spores had surface ridges. The morphological features of the telio- and mesospores agree with those described for P. lagenophorae. To the authors' knowledge, this is the first record of a rust fungus on English daisy in North America. The inoculation experiments indicated that the rusts on English daisy and common groundsel are not biologically separated, casting doubt on the taxonomic concept of Weber et al. (4) that considered the rust on English daisy to be a distinct species, P. distincta McAlpine (although they did not examine type material of either P. lagenophorae or P. distincta). References: (1) M. Scholler. Sydowia 49:174, 1997. (2) M. Scholler. J. Plant Dis. Prot. 105:239, 1998. (3) M. Scholler and S. T. Koike. Plant Dis. 85:335, 2001. (4) R. W. S. Weber et al. Mycol. Res. 102:1227, 1998.


Author(s):  
Amy E. Kendig ◽  
S. Luke Flory ◽  
Erica M. Goss ◽  
Robert D. Holt ◽  
Keith Clay ◽  
...  

Abstract Plant-pathogen interactions occur throughout the process of plant invasion: pathogens can acutely influence plant survival and reproduction, while the large densities and spatial distributions of invasive plant species can influence pathogen communities. However, interactions between invasive plants and pathogens are often overlooked during the early stages of invasion. As with introductions of invasive plants, the introduction of agricultural crops to new areas can also generate novel host-pathogen interactions. The close monitoring of agricultural plants and resulting insights can inform hypotheses for invasive plants where research on pathogen interactions is lacking. This chapter reviews the known and hypothesized effects of pathogens on the invasion process and the effects of plant invasion on pathogens and infectious disease dynamics throughout the process of invasion. Initially, pathogens may inhibit the transport of potentially invasive plants. After arrival in a new range, pathogens can facilitate or inhibit establishment success of introduced plants depending on their relative impacts on the introduced plants and resident species. As invasive plants spread, they may encounter novel pathogens and alter the abundance and geographic range of pathogens. Pathogens can mediate interactions between invasive plants and resident species and may influence the long-term impacts of invasive plants on ecosystems. As invasive plants shift the composition of pathogen communities, resident species could be subject to higher disease risk. We highlight gaps in invasion biology research by providing examples from the agricultural literature and propose topics that have received little attention from either field.


2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Tom Maurice Fayle ◽  
Katerina Sam ◽  
Anna Humlova ◽  
Luciano Cagnolo ◽  
Vojtech Novotny

Weed Science ◽  
1976 ◽  
Vol 24 (3) ◽  
pp. 261-265 ◽  
Author(s):  
G. F. Ryan

Over a 3-yr period 10 herbicides were tested alone or in combination for control of weeds and for effects on growth of nursery stock in containers. Annual bluegrass (Poa annuaL.) was controlled by norea [3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea], alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], and combinations of diphenamid (N,N-dimethyl-2,2-diphenylacetamid), trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), and nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline] plus simazine [2-chloro-4,6-bis(ethylamino)-s-triazine]. Bittercress (Cardamine oligospermaNutt.) was controlled by simazine, oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one], and norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone]. Mouseear chickweed (Cerastium vulgatumL.) was controlled by dichlobenil (2,6-dichlorobenzonitrile) and norflurazon, and common groundsel (Senecio vulgarisL.) was controlled by dichlobenil and norflurazon. Some of the treatments decreased growth of certain nursery cultivars.


Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 229-232 ◽  
Author(s):  
S. R. Radosevich ◽  
O. T. Devilliers

The distribution of simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] in whole plants and the effect of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] on isolated leaf cells and chloroplasts of two biotypes of common groundsel (Senecio vulgarisL.) were studied. Both biotypes accumulated14C at the leaf margins 60 hr after exposure of roots to14C-simazine. No difference in herbicide distribution between the two biotypes was observed. Atrazine (10 μM) inhibited photosynthesis, RNA synthesis, and lipid synthesis in isolated susceptible (S) cells but not resistant (R) cells. Lipid synthesis in S cells but not R cells was enhanced by exposure to 1 and 0.1 μM atrazine for 1 hr. Photochemical activity of R chloroplasts was not inhibited by atrazine but S chloroplasts were severely inhibited.


Ecology ◽  
1985 ◽  
Vol 66 (4) ◽  
pp. 1261-1269 ◽  
Author(s):  
Arthur E. Weis ◽  
Warren G. Abrahamson

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