Hi Radwa,

For Arabidopsis you need to use  the 2 cm2 chamber instead of the one you are using now. This chamber will fully cover the leaves of Arabidopsis plants growing under short-day conditions.

For details (including a photo of the chamber you need to use) please see the article of Flexas (2007) 'Mesophyll conductance to CO2 in Arabidopsis thaliana'

Dear Radwa,

One possibility is culture Arabidopsis plants under short-day conditions. In Flexas et al. 2007 (New Phytologist 175) you will find further indications.

Regards

SG Nebauer

Not sure if you have the funding for it, but LI-COR does sell chambers for Arabidopsis (http://www.licor.com/env/products/photosynthesis/chambers/arabidopsis.html). 

Hello Radwa Mohamed,

It looks like you have an all around chamber. Its good for much everything, but not specific enough for your job. Well, Li-Cor has chambers that are specific to Arabidopsis. Please see here: http://www.licor.com/env/products/photosynthesis/chambers/arabidopsis.html

Also, I believe you do not need to fill the entire chamber with leaf. I worked with pine trees and the chamber was 2x6cms. Each pine needle was 2mm broad at max. Try testing the chamber with other size leafs (other species) and see if you get similar results.

Regards

Gilor: thanks alot, unfortunately am not in access to the small chamber and that's why I need to find some other way to measure conductance.

Sergio: I am growing plants now in short-day conditions but I still don't think they will hit the 6 cm square ever! adding nutrient solution is another thing I might try too, thanks alot for your answer.

What do you think about putting two leaves in the chamber? would that help overcoming the area insertion problem?

thanks again for you both

R. Mohamed

Hello Radwa,

I think you should consider weighing or measuring the leaf area into the chamber, whatever you will use (in the case that one leaf fully covered the chamber, the leaf area is a known value). If you introduce more than one leaf (also whole plant) into the chamber, take into account the possibility of shade between the leaves.

Hi Radwa,

In your situation, I normally used the same method as suggested by Mario. I measured small leaves (broadleaf) with the 2x6 cm chamber without any problem. It's not necessary to fill the whole chamber opening with the leaf.  I just put in one leaf, do the measurement, then cut the leaf off and scanned it to determine the actual leaf area that was enclosed in the chamber. After that, recalculated the photosynthetic rate / conductance by multiplying the data from the LI-COR with the ratio of actual leaf area / 12 cm2.

Regards

Hi Pak:

Thanks alot, I guess this will be sufficient, but let me just try to understand more:

you will setup the machine on certain leaf area? then use it to calculate the ratio after measuring the leaves? sorry if this should be easy to get.

thank you

Radwa

Hi Radwa,

Yes, that's right.  You still set the LI-COR with a leaf area of 6 cm2 as you normally do(sorry that I made a mistake in my last message, the correct dimensions of the broad leaf chamber is 2x3 cm2).  Then redo the calculation using the ratio.

Regards

Pak

Thanks all for such help :)

Hi Radwa,

If you use photoautotrophic micropropagation method, you can obtain larger leaf areas. Then you can measure with an Arabidopsis chamber for leaf area of 1x1 cm2.

Regards,

Quynh Nguyen

You can also use whole rosettes if you adapt your chamber. Alternatively the suggestions above for growing bigger leaves are also good, you can get also huge plants when optimally fertilizing the plants. However, you may wonder whether this wouldchange the properties per se.

Goodluck,

Tony

Hi,

Thanks alot for your replies ~:)

Just wanted to mention I have my plants growing in 8 hours light (short-day) conditions) and looks promising so far. I will give it a go with fertilizing although I don't know what kind of effects it might have on my results. thanks again.

At least when you fetrilöze all lines that you are comparing you should be on the safe side,

Tony

Growing the plants at a cold temperature also encourages slow growth and larger leaves.

As I think, It would be good if you will change the chamber area (smaller chamber) nothing else. Because when you will change the other things like temperature then those would not be considered as normal growth conditions.

If you work out the leaf area of your plant before measuring, you can adjust the leaf area on the Licor before taking your measurement and it recalculates it all for you. (on the leaf area button).

Thanks all, just wanted to add, I finally obtained the area to cover the LiCor chamber.

Plants were grown in a 8 hours day length, and they are now about 75 days old, haven't started flowering yet.

Next step, I will try using the nutrient solution to obtain the same area in shorter time.

Thanks alot for your help :)

Another thing is that you can buy one additional LiCor chamber (the smallest one) which can be used for Arabidopsis leaves.

Look at: Flexas et al. 2007 New Phytol.175(3):501-11.

Mesophyll conductance to CO2 in Arabidopsis thaliana.

In any case, the short day conditions were the better option