Detection of Chlorophyll fluorescence at crop canopies level: … · 2018. 7. 16. · Detection of...

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Detection of Chlorophyll fluorescence at crop canopies level: Remote Sensing of Photosynthesis

Part I : Background, central and alternative photosynthetic electron transport pathways

and active fluorescence measurement

Oded Liran Department of Precision Agriculture


Photosynthesis is the main driver of the global carbon cycle

Earthhow.com


Specialized organelles within the leaf mesophyll trap light energy and transform it into chemical energy

(Drusch, M, 2017)

The light dependent reactions of the photosynthetic apparatus are a series of transmembrane and soluble protein complexes located

within the thylakoid membranes in the chloroplast


pung5.wikispaces.com

https://pung5.wikispaces.com/Group+2




(Wei-Zong H, 1992)

(WikiVisually.com)

Photosystem II & I are multi pigment-protein complexes that convert physical to chemical energy and drive the electron transport chain


Photosynthetic pigments capture light energy from different regions of the electromagnetic spectrum

Energy transferred to chlorophylls excite electron to a higher energy level which can then relaxed back in various different transition states


Photochemistry (..to primary acceptor)

Interaction with Oxygen

(…to ROS) (Sciencedump.com)


Light harvesting complexes funnel down absorbed light by energetic transfer towards the reaction centers of PSII and PSI

DOI: 10.5772/67887

Quantum Coherence (Anna JM, 2013)

Forster Resonance Energy Transfer (Knox RS, 2002)


Excitation which results in electron transfer to the primary acceptor of PSII, can continue in a non-cyclic pathway towards the

FNR – Ferredoxin:NADP+ Reductase (H2O -> NADPH pathway)


NADPH and ATP created in the light dependent reactions of photosynthesis are used in the Calvin-Benson-Bassham cycle

in order to produce sugars- the building blocks of life

(Wikipedia)


Alternative electron transport pathways modulate energy distribution between the two Photosystems

Active at the beginning of a light period to account for ATP needed to activate CBB cycle (Joliot 2002)

Yamori W, 2016

Used as a part of a photoprotection Mechanism in order to avoid oxidative stress to the chloroplast (Yamori W, 2015)


(Skillman JB, 2011)

Mehler reaction is elevated under water stress condition (Asada, 2000)

Alternative electron transport pathways modulate energy distribution between the two Photosystems (H2O -> H2O cycle)

The photosynthetic light reactions are limited by the activity of the Calvin-Benson-Bassham cycle carbon fixation step

(Teiz and Zeiger, 3rd edition)

13 11

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14 12

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The photosynthetic apparatus obtains time dependent lines of defense in order to protect itself from reaching an oxidative stress

otherwise known as Non-Photochemical Quenching

Seconds to minutes:

qE = Energy Dependent Non photochemical quenching (xanthophyll cycle)

Minutes to hours:

PQ

qT = Light Harvesting Complex state transition towards PSI

qI = reversible photoinhibition (closure of damaged Photosystem II units)

Hours to days:

(Dent RM, 2001)


The photosynthetic apparatus reaches a sustained photoprotection conditions especially in the winter

• CBB cycle activity is slowed down

• The Photosynthetic apparatus is found on sustained NPQ conditions (Porcar-Castell, 2011) • Most of the energy of light is dissipated on the antenna (Nilkens M, 2010)

When illuminating Chlorophyll extract from plants : When illuminating a leaf

About 90% of the light is emitted back to the viewer How much will be emitted back to the viewer ?

“In making a strong beam of the sun’s light pass through the green fluid, I was surprised to observe that its color was a brilliant red, complementary to the green…” - Sir David Brewster, 1834

Active measurement of chlorophyll fluorescence requires a special flourometer that manipulates the photosynthetic apparatus

performance in a unique way


https://www.youtube.com/watch?v=_qZjKKRNBCU

(Kautsky and Hirsch, 1931)


Upon switching on the light, a fast fluorescence induction is recorded followed by a slower relaxation (fluorescence quenching)

(McAlister & Myers, 1940)

Both of the wheat samples were illuminated for ~10 minutes in strong light, however, (1) and (2) were let to relax in the dark for 20 and 60 minutes respectively

Fluorescence

CO2 assimilation

Fluorescence induction and CO2 assimilation takes on opposite behavior within a light period


(Flors C, 2006)

On 1963, Duysens and Sweers experienced a constant fluorescence profile after application of Diuron: Di-Chlorophenyl dimethyl Urea


Application of a photosynthetic electron transport chain inhibitor results in a continuous excitation of fluorescence

DCMU

(Bonasera KF, 2006)

We can use the OPENED/CLOSED PSII principle to our advantage !


Application of a photosynthetic electron transport chain inhibitor results in a continuous excitation of fluorescence

P680

Pheo

Qa

Qb

3 psec

20 nsec

200 nsec

200 µsec

600 µsec

20 nsec

*

H2O 22

12 OeH

Energy


Short and strong pulsed light reports on the PSII state on top of continuous light experiments

1 µsec 0.05 µE

200 µsec ~10,000 µE

How much short ?

(Schreiber U, 1986)


Summary of the First part of the Lecture: 1. The global Carbon cycle affect the greenhouse effect, ocean acidification and the global eco-physiology of all life on earth. 2. The Plants (unicellular and multicellular) are the main driver for the carbon cycle, as they are responsible for Gross Primary Production, that is the utilization of light energy in chemical reactions that produce sugars. 3. The photosynthetic apparatus uses the absorbed light energy in various biosynthetic pathways the main of which is sugar biosynthesis. 4. We can use the photosynthetic apparatus properties to our advantage and to study the activity state of the Photosystem II.

Thank you for your attention

1. https://earthhow.com/carbon-cycle/

2. Drusch, Matthias, et al. "The FLuorescence EXplorer Mission Concept—ESA’s Earth Explorer

8." IEEE Transactions on Geoscience and Remote Sensing 55.3 (2017): 1273-1284. 3. pung5.wikispaces.com 4. http://mendel.berkeley.edu/~wzh/chapter3/text.html 5. https://wikivisually.com/lang-de/wiki/Photosystem_I 6. Guidi, L., Tattini, M., & Landi, M. (2017). How Does Chloroplast Protect Chlorophyll Against Excessive Light?.

In Chlorophyll. InTech. 7. Anna, J. M., Scholes, G. D., & van Grondelle, R. (2013). A little coherence in photosynthetic light

harvesting. BioScience, 64(1), 14-25. 8. Knox, R. S., & Van Amerongen, H. (2002). Refractive index dependence of the Förster resonance excitation

transfer rate. The journal of physical chemistry B, 106(20), 5289-5293. 9. http://www.sciencedump.com 10. http://www.life.illinois.edu/govindjee/Z-Scheme.html 11. Yamori, W., Makino, A., & Shikanai, T. (2016). A physiological role of cyclic electron transport around

photosystem I in sustaining photosynthesis under fluctuating light in rice. Scientific reports, 6, 20147. 12. Asada, K. (2000). The water–water cycle as alternative photon and electron sinks. Philosophical

Transactions of the Royal Society of London B: Biological Sciences, 355(1402), 1419-1431. 13. Skillman, J. B., Griffin, K. L., Earll, S., & Kusama, M. (2011). Photosynthetic Productivity: Can Plants do

Better?. In Thermodynamics-Systems in Equilibrium and Non-Equilibrium. InTech. 14. Taiz, L., & Zeiger, E. (2002). Plant Physiology, Sinauer Associates.


References:

https://earthhow.com/carbon-cycle/








http://mendel.berkeley.edu/~wzh/chapter3/text.html




https://wikivisually.com/lang-de/wiki/Photosystem_I




http://www.sciencedump.com/

http://www.life.illinois.edu/govindjee/Z-Scheme.html




15. Dent, R. M., Han, M., & Niyogi, K. K. (2001). Functional genomics of plant photosynthesis in the fast lane using Chlamydomonas reinhardtii. Trends in plant science, 6(8), 364-371. 16. Porcar‐Castell, A. (2011). A high‐resolution portrait of the annual dynamics of photochemical and non‐photochemical quenching in needles of Pinus sylvestris. Physiologia Plantarum, 143(2), 139-153. 17. Nilkens, M., Kress, E., Lambrev, P., Miloslavina, Y., Müller, M., Holzwarth, A. R., & Jahns, P. (2010). Identification of a slowly inducible zeaxanthin-dependent component of non-photochemical quenching of chlorophyll fluorescence generated under steady-state conditions in Arabidopsis. Biochimica et Biophysica Acta (BBA)-Bioenergetics, 1797(4), 466-475. 18. Kautsky, H., & Hirsch, A. (1931). Neue versuche zur kohlensäureassimilation. Naturwissenschaften, 19(48), 964-964. 19. McAlister, E. D., & Myers, J. (1940). Time course of photosynthesis and fluorescence. Science, 92(2385), 241-243. 20. Flors, C., Fryer, M. J., Waring, J., Reeder, B., Bechtold, U., Mullineaux, P. M., ... & Baker, N. R. (2006). Imaging the production of singlet oxygen in vivo using a new fluorescent sensor, Singlet Oxygen Sensor Green®. Journal of experimental botany, 57(8), 1725-1734. 21. Bonasera, J. M., Meng, X., Beer, S. V., Owens, T., & Kim, W. S. (2004, July). Interaction of DspE/A, a pathogenicity/avirulence protein of Erwinia amylovora, with pre-ferredoxin from apple and its relationship to photosynthetic efficiency. In X International Workshop on Fire Blight 704 (pp. 473-478).

References:


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