Improving Yield Flashcards
NPQ - basics
High levels of zeaxanthin turns on NPQ
Cloudy = high photosynthetic efficiency as using all available light
Becomes sunny = decreased efficiency as not using all light; NPQ turned on to protect from bleaching as high zeaxanthin
Becomes cloudy = NPQ off but takes time to increase photosynthetic efficiency as still high zeaxanthin and less CO2 fixation
If it remains cloudy, NPQ turns off and zeaxanthin converted to violaxanthin; more CO2 fixation
NPQ - improving
Make it faster to turn off to get photosynthetic efficiency to max
Express more enzymes to speed up xanthophyll cycle and relaxation of NPQ (zeaxanthin epoxidase)
Mutant plants have lower NPQ levels so increase yield
Alter photorespiration
Make less 2 phosphoglycolate and more 3 phosphoglycerate; takes lots of energy to convert and prodcues CO2 and NH3
Shortcut to remove 2 phospho:
New enzymes into chloroplast
Alternate pathways- turn glycolate into CO2 and malate using enzymes and express only in chloroplast (malate synthase & glycolate dehydrogenase)
Higher max photosynthetic rate, max quantum yield, biomass and yield
Speed up photosynthesis
Widen bottlenecks in e- transport chain: plastocyanin protein slow to accept and pass on e- so add cytochrome protein
CB cycle: SBPase enzyme slow and non specific so add faster version and more of it
Both increase biomass and yield, increase WUE as stomata open less so less transpiration
Light use
Change to light abrupt but plants slow to adapt incase whether changes - conserve energy and survive
Turn photosynthesis on and off faster
Optimal dynamic acclimation
???
Plant architecture
Model: image sequence, point cloud, filter segmentation, structure fitting, phenotype parameter extraction
Ideal canopy: erect, pale leaves at top w rapid rubisco enzymes, lots of small light harvesting complexes; flat dark leaves at bottom w specific rubisco enzymes, few but large light harvesting complexes
Sugar cane - double row spacing best
