Genomes available to study at http://www.phytozome.org/1.Arabidopsis2.Fast plant3. Sorghum4. Brachypodium distachyon5. Amaranthus (C4 dicot)6. Quinoa7. Kalanchoe8. Venus fly traps9. C3 vs C4 Atriplex10. C3 vs C4 Flaveria11. C3 vs C4 Panicum12. P. oleracea C4-CAM 13. P. afra C3-CAM 14. M. crystallinum C3-CAM

Genomes available to study at http://www.phytozome.org/(most can also be searched atwww.Gramene.org)

Brachypodium distachyon

Brachypodium distachyonFlowering•Long-days (20 hours, but not 14)•Most diploid varieties have absolute requirement for vernalization

Brachypodium distachyonFlowering•Long-days (20 hours, but not 14)•Most diploid varieties have absolute requirement for vernalizationNo mention of GA, CO2 or high T effects!

Brassica rapa (fast plants)http://www.fastplants.org/resources/kinds_of_plants.php

Flowering time varies widely between different accessions (turnips, chinese cabbage, Pak choi, fast plants)•Long-days •Some varieties require vernalization, others do not!

Brassica rapa (fast plants)•Some varieties require vernalization, others do not!•Select against early flowering in crops to increase yield, low T can trigger early flowering•Have 4 FLC alleles, flowering time & vernalization requirement depends on alleles (& splicing variants)

Brassica rapa (fast plants)•Some varieties require vernalization, others do not!•Select against early flowering in crops to increase yield, low T can trigger early flowering•Have 4 FLC alleles, flowering time & vernalization requirement depends on alleles (& splicing variants)•Lots of work on low T & photoperiod, didn’t find any on CO2 or high T.

Arabidopsis thaliana•Very extensive studies on photoperiod, low and high T on flowering and some on CO2

• High T accelerates flowering• Recently identified a QTL affecting flowering at

elevated CO2

Portulaca oleracea Many studies on effects of temperature and photoperiod on germination•Most omega-3 fatty acids of any plant seed!•http://rareseeds.com/herbs/purslane/purslane-green.html

Transition to FloweringAdults are competent to flower, but need correct signalsVery complex process!Can be affected by:• Daylength• T (esp Cold)• Water stress• Nutrition• Hormones• Age

Transition to FloweringCan be affected by nutritionPi deprivation induces miR399Travels in phloem to repress PHO2, a neg regulator of Pi

uptakemiR399 enhances TSF expressionSucrose enhancesmiR399 expression(also many other genes)miR399 is Temp S!

Water TransportIn leaf water passes to mesophyll, then to air via stomatesDriving force = vapor pressure deficit (VPD)• air dryness•∆ H2O vapor pressure [H2O(g)]& saturated H2O vapor pressure• saturated H2O vapor pressurevaries with T, so RH depends on T• VPD is independent of T: says how fast plants lose H2O at any T

Water Transport Rate depends on pathway resistances• stomatal resistance

Water Transport Rate depends on pathway resistances• stomatal resistance• Controlled by opening/closing

Water TransportRate depends on pathway resistances• stomatal resistance• boundary layer resistance• Influenced by leaf shape & wind

Light regulation of Plant DevelopmentLight regulation of Plant DevelopmentPlants use light as food Plants use light as food andand information informationUse information to control developmentUse information to control development

Light regulation of Plant DevelopmentLight regulation of Plant DevelopmentPlants use light as food Plants use light as food andand information informationUse information to control developmentUse information to control development•germinationgermination

Light regulation of Plant DevelopmentLight regulation of Plant DevelopmentPlants use light as food Plants use light as food andand information informationUse information to control developmentUse information to control development•GerminationGermination•Photomorphogenesis vs skotomorphogenesisPhotomorphogenesis vs skotomorphogenesis

Light regulation of Plant DevelopmentLight regulation of Plant DevelopmentPlants use light as food Plants use light as food andand information informationUse information to control developmentUse information to control development•GerminationGermination•Photomorphogenesis vs skotomorphogenesisPhotomorphogenesis vs skotomorphogenesis•Sun/shade & shade avoidanceSun/shade & shade avoidance

Light regulation of Plant DevelopmentLight regulation of Plant Development•GerminationGermination•MorphogenesisMorphogenesis•Sun/shade & shade avoidanceSun/shade & shade avoidance•FloweringFlowering

Light regulation of Plant DevelopmentLight regulation of Plant Development•GerminationGermination•MorphogenesisMorphogenesis•Sun/shade & shade avoidanceSun/shade & shade avoidance•FloweringFlowering•SenescenceSenescence

Light regulation of growthPlants sense1. Light quantity

Light regulation of growthPlants sense1. Light quantity2. Light quality (colors)

Light regulation of growthPlants sense1. Light quantity2. Light quality (colors)3. Light duration

Light regulation of growthPlants sense1. Light quantity2. Light quality (colors)3. Light duration4. Direction it comes from

Light regulation of growthPlants sense1. Light quantity2. Light quality (colors)3. Light duration4. Direction it comes fromHave photoreceptorsthat sense specific wavelengths

Light regulation of growthEarly work:• Darwin showed that phototropism is controlled by blue light

Light regulation of growthDuration = photoperiodism (Garner and Allard,1920) Maryland Mammoth tobacco flowers in the S but not in N= short-day plant (SDP)Measures night! 30" flashes during night stop flowersLDP plants such as Arabidopsis need long days to flowerSDP flower in fall, LDP flower in spring, neutral flower when ready

Light regulation of growthMeasures night! 30" flashes during night stop flowersLDP plants such as Arabidopsis need long days to flowerSDP flower in fall, LDP flower in spring, neutral flower when readyNext : color matters! Red light works best for flowering

Light regulation of growthNext : color matters! Red light (666 nm)works best for flowering & for germination of many seeds!

PhytochromeNext : color matters! Red light (666 nm)works best for flowering & for germination of many seeds!But, Darwin showed blue works best for phototropism!

PhytochromeNext : color matters! Red light (666 nm)works best for flowering & for germination of many seeds!But, Darwin showed blue works best for phototropism!Different photoreceptor!

PhytochromeBut, Darwin showed blue works best for phototropism!Different photoreceptor!Red light (666 nm) promotes germinationFar red light (>700 nm) blocks germination

PhytochromeBut, Darwin showed blue works best for phototropism!Different photoreceptor!Red light (666 nm) promotes germinationFar red light (>700 nm) blocks germination

PhytochromeRed light (666 nm) promotes germinationFar red light (>700 nm) blocks germinationAfter alternate R/FR flashes last flash decides outcome

PhytochromeRed light (666 nm) promotes germinationFar red light (>700 nm) blocks germinationAfter alternate R/FR flashes last flash decides outcomeSeeds don't want to germinate in the shade!

PhytochromeRed light (666 nm) promotes germinationFar red light (>700 nm) blocks germinationAfter alternate R/FR color of final flash decides outcomeSeeds don't want to germinate in the shade!

Pigment is photoreversible