L1- intro

Question 1

whats interesting about plant development

Answer 1

most of the plant development is post-embryonic
germ cells are established later

• plants are sessile organisms, plant cells are bounded by cellulose cell walls, plant development is highly plastic (but still steotyped recognise an oak tree as oak, and aradopsis as aradopsis)

Question 2

what is phenotypic plasticity in ploygonum vespitosum

Answer 2

the look of this plant is very different if grown in dry, full sun compared to in wet with partial shade

Question 3

what signal types do plants have

Answer 3

internal v external signals
this is why development is so flexible

Question 4

where does signalling occur

Answer 4

at many stages
- intracellular
- local
- systemic
-between plants
- between generations

they lead to physiological and developmental changes

Question 5

is regulation of meristem activity complex or simple

Answer 5

complex
relies on chromatin remodelling, microRNAs, small peptide, receptors, transcription factors, plant growth regulators ect

Question 6

what plant hormones are important

Answer 6

auxin
gibberellin
ethylene
jasmonic acid
salicylic acid

abscisic acid

Question 7

what are Ca2+ signals

Answer 7

intracellular signal
- changes in [Ca2+]cyt occur in response to numerous extracellular signals

challenging to measure-
-concentration is low
- changes are transient
-sub-cellular location important
- cell specific

Question 8

how would you measure [Ca2+]cyt concentrations

Answer 8

inject Ca2+ sensitive dye, such as INDO-1, FURA-2

use transgenic plants to synthesise Ca2+ sensitive proteins
eg aqueorin, cameleon
-detect changes using optical microscopy

FRET, Forster resonance energy transfer- in the absence of Ca2+ excitation, at 440 nm in fluorescence at 480 and 535nm
in the presence of Ca2+, at 440 nm results in increased fluorescence at 535nm, the ca2+ causes the two FPs to come into close contact allowing energy to be transferred

• changes here are seen in repsonse to mechanical stimulation, in gaurd cells in response to ABA, rise of syosolic Ca2+ cause stomatal closure but oscillations of different frequencies, cause different repsonses

but different frequencies of Ca2+ oscillation encode different information, different stimuli repsonse in different response and different frequencies, so the number, period and duration of oscillations important