Cold Stress
Introduction
different types
chilling
Freezing
impacts
tropical
0-20
Vegative
reprodcutive
temeprate below 0
drama due to cliamte change as erreacit weather
can have different levels of susceptiablity
different physilocogal changes
chilling
freezing
cold hardy
Decting stress and intial respose
unsure exaclty how plants detict cold stress
2 theroies of primary repsosne
phytochrome B senses tmeerpature
phase transion thery. chnage of plamsa mebrare from liquid-cyrstyline to solid gel
this reduces fluidy, changes perambitly, changes activation encery
nice diagram showign this. this all casues damage from cold
calisum influc throusy. sunndenn membrane deoplistion Ca incases into cytsosl. dont knwo whcih stanportes. have opening of stomate which give whilting. also gene expression changes
aviodence
overwinter dormancy, distribtuion of diff speices and sucsptablity of cold
Vegatiative stage
DEFENCES
14-3-3 protines
phosopholipase C and D
lots of pathways activeted by these
phopostliase D produces somethign which regualtes H+-ATPase. imporantant
Ca2+ pathways
Ca related ot lots of abioitc stresses
Ca entres th cell through unknonw channels. interacts with lot sof diff moluces. can listen to recording
cold repsonive protines. photpyled, tranlosted inot nurlces and bind to CBF.
Cold acclimation
changes in gene tolerance in response to non-freezing that allow freezing tolerance
Missed a few slides here
Future outlook
more knowledge on snesing and primary resposne
GM crops
Reproduction
Stages
Global warming
the sea stores and trnasports lots of heat
the atomosphers plays a role
the tilted axis of the earth and its rotation aroudn the sun
astomphore temp inreaces, which de-stalibes the large areas of cold polar air into higher latitidues.
gives large, extremem temo chanegs out of season
Urbansitions
less land to grow crops on. in asia farmer have to go to higher altitudes to get enoguh space. but low yeild as too cold
Flower devleopment
male and femail folar parts devlopmetn
Sporgonsisi
development gametes
polation
gamertogneisis
fertistions
All of these stages are senstive to cold temp but pollen production is the most severly effected
temp casues lots of issues in pollen production effecting every stages leading abonoralites and sterility
ABA
cold stress duering respotive devlepment cuases incasre in ABA
ABAB could be a singal
upreduclated NCED£ and ZEP
Giberallin
no plamsdomsamd around polen with sugars. enxymes transport but ABA inhibits enzyme. build up of hexose in leaves and staravation to the devloping pollen
hormone that regulates plant development porcesses
cold increases DELLA which inhbits gibs
gibs regulatae amylatse synathises in the GAMYB pathway.
low temp - more della - less gib - less synthisis of strach
starch imparntat in vaiabilty of pollen
Rice study
upredulated bZIP71 and bZIP73
enchanced cold toldere at repoductive stage by reducing ABA levlels
made diff lines of transgenci rice
cuases increase in yeild when grown in field