I am trying to investigate the effect of phosphorus stress on Arabidopsis plants grown in hydroponic media and found that (Conn et al, 2013) stated the correct PO43- concentration is 0.6 mM.
Does anyone knows what Pi concentration would be a severe Pi-deficient condition?
Dear Carlos,
I think 0.6 or 0.67 mM is an optimal supply level in Hydroponic culture. Arabidopsis is a weed and should be very efficient in nutrient uptake. Even at 0.1 mM supply, Arabidopsis did not show any P deficiency symptoms. I therefore hope a supply of 5-20 µM would be appropriate see some P deficiency symptoms in Arabidopsis.
5 to 10 uM is a good concentration to trigger the Pi-deficiency response in Arabidopsis and still maintain reasonable growth. You can easily detect P deficiency in your syste by monitoring anthocyanin accumulation and if necessary a simple PCR reaction to monitor the increased expression of one or tow of the classical low-Pi responsive genes, such as SPX1, AtPT1, etc.
Thank you all for your responses. I think I´ll first try to set up a control condition with 0.5-0.7 mM Pi and a starvation condition with 10 uM Pi. I´ll read carefully Luis´ paper about hydroponics.
Luis, do you think measuring PHO2 or IPS1 mRNA levels would be OK to detect Pi deficit stress on the plants??
PHO2 and IPS1 are both good marker for the low phosphite response.