Plant-Animal interactions Flashcards
Plants
- autotrophs: primary producers that energise our planet
- provides food and a habitat
- the basis for radiations in animals is the resources provided by plants
As we climb the trophic ladder,
species richness can increase by orders of magnitude
Describe a hypothetical oak tree ecosystem
- host several hundred insect herbivore species
- each of these may be utilised by 10-20 species of carnivore or parasite
Define predation of plants by animals
plants consumed by animals (without benefit to the plant)
Describe predation of animals by plants
- plants attract, trap and digest animal prey
- e.g. Carnivorous plants
Describe pollination (plants) by deception (animals)
- plants ‘dupe animals with olfactory/visual deception into pollinating them, with no reward to the animal
- e.g. Bee orchid sapromyiophily
Describe symbiosis between plants and animals
- species-specific plant-animal relationships
- pollination, seed dispersal and completion of life cycles, myrmecophytes
Describe plants and predation
Plants have evolved numerous defences both chemical and physical
Describe sapromyiophily
- pollination by deceit
- composition of volatiles from these flowers and from a rotting carcass is strikingly similar
- pollinators respond in the same way to chemicals from both sources
- remarkably complex mimicry must have evolved to exploit insects as unrewarded pollinators
Give a sapromyiophilous species
Helicodiceros muscivorus
Describe the VOCs produced by sapromyiophilous species
oligosulphides
Describe convergent sapromyiophily
- emerged 4 times
- Piperales, Alismatales, Malphigiales, Gentaniales
Define carnivorous plants
- Attract and capture prey using leaf-derived traps
- Kill the captured prey
- Digest the captured
prey - Absorb nutrients from
the prey - Benefit from those
nutrients
Describe the evolution of plant carnivory
- evolved independently in at least 6 major clades
- rare phenomenon
- evolution associated with extreme alterations in morphology
- 600+ carnivorous species
- evolved in response to nutrient economics: typically in water-logged, acidic, mineral-poor conditions;
- remarkable diversity
Carnivorous plant lineages
- Alismatales
- Poales
- Caryophyllales (Nepenthes)
- Oxalidales (Cephalotus)
- Ericales (Sarraceniaceae)
- Lamiales
- (Malphigiales)
- (Asterales)
Describe the ‘stereotype trap’ forms
- snap
- sticky
- pitfall
Describe pitcher plants
- remarkable convergence of traits associated with carnivory
- common solution to the problem of nutrient deficiency evolved across unrelated lineages
Describe the Nepenthes pitcher structure
- lid
- peristome
- pitcher
Describe the functional surfaces of the Nepenthes pitcher
- peristome
- waxy zone
- viscoelastic fluid
Describe other features of a Nepenthes pitcher
- nectar gland
- peristome epidermal cells
- lunate cells
- digestive glands
Describe the Order Caryophyllales
- include cacti, carnations and many carnivorous plants
- 33 families (6% of all eudicots)
- flypaper traps such as Sundews (Drosera spp.)
- snap traps (Dionaea)
- also Nepenthaceae
- multiple stereotype trap forms
Describe mechano-sensitive traps
- touching triggers hairs
- activates mechano-sensitive ion channels
- mechano-sensors generate bio-electrochemical signal that acts as an action potential; activates motor cells
Describe Triphyophyllum
- ‘missing link taxon’
- multiple leaf forms on one plant
Describe evolution of the Nepenthes pitcher
- adhesive glands: precursors to
tentacles - foliar folding and
marginal fusion of glandular leaf
Describe Nepenthes gracilis
- an ant-specific trap
- novel trapping mechanism
- unique, semi-slippery wax crystal surface on the underside of the horizontal, stiff lid
- secreted more nectar under the lid and less on the peristome; directing prey mainly towards the lid
- utilises impact of rain drops to ‘flick’ insects into the trap (confirmed with simulated rain)
Nepenthes albomarginata
a termite-specific trap
Nepenthes ampullaria
a detritivore
Nepenthes lowii
- ‘tree shrew toilet’
- faecal capture
- flattened large scale ridges
- reduction in small scale ridges
Nepenthes rajah
‘tree shrew toilet’
Nepenthes hemsleyana
a bat roosting site
Describe faecal capture
- substantial changes to nutrient acquisition strategies in carnivorous plants may occur through simple modifications to trap geometry
- at least four species show adaptations for mammalian faecal capture
Describe the diversity of Nepenthes pitcher plants
- adaptations to differences in local prey assemblages
- diversity of pitcher geometries in association with different prey
- adaptive radiation
- detritivore; defecation + feeding; defecation + roosting
- may drive such divergence and speciation
Describe myrmecophytes
- domatia
- food bodies
- extrafloral nectar
- plants that evolved across about 50 families to produce modified structures that host ant colonies in return for defence and/or nutrients
Describe the types of ant-plant interactions
- opportunistic and facultative interactions (protection against herbivores)
- seed dispersal by ants attracted to seed-associated food bodies called elaiosomes
- more intimate obligate interactions (e.g. ant–plant symbioses)
