A Method for Hydroponic Culture of Arabidopsis thaliana

Developed by Anka Zwieniecka, Anna Gorska, and Jillian Lazor

MATERIALS

Plant Material

Equipment and Chemicals

Germination of A. thaliana
	Step 1 The opaque plastic tray was filled with PRO-MIX Professional General Purpose Growing Medium soil (Premier Horticulture, Canada), over which the A. thaliana seeds were generously sprinkled. The plastic growth tray was then covered with a transparent plastic lid. The junction between lid and tray was sealed with parafilm, and the lid was wrapped in aluminum foil to prevent penetration of light. The covered tray was then placed in a cold room at 4慢 for 7 days.
	Step 2 Thereafter, the aluminum foil was removed and the seeds were transferred to a controlled environment growth chamber. The seeds were germinated and the seedlings were grown at a 16h, 24慢 day and 8h, 18慢 night regime, under fluorescent and incandescent light with a photon flux density of 170 痠ol/m2s, and at a relative humidity of 65%.
	Step 3 The seedlings remained covered with the transparent plastic lid to maintain moisture until 1 week after germination. The germinated seedlings were then uncovered and watered with a frequency sufficient to maintain soil moisture.
Preparation of Hydroponic Culture Boxes
	Step 1 Hydroponic growth containers were constructed of 6.5 L opaque, blue plastic boxes (30 cm x 17.5 cm x 13 cm). Fourteen holes, 1 cm in diameter, were drilled in the lid of each box, each hole intended to serve as a support for a single seedling. An additional hole, also 1 cm in diameter, was drilled to serve as conduit through which tubing to provide aeration could pass. Thereafter, each box was filled with 6.5 L of high nitrogen, modified Hoagland solution (final concentration of nutrients: 603 然 Ca(NO3)2, 795 然 KNO3, 190 然 KH2PO4, 270 然 MgSO4, 2 然 MnSO4, 0.085 然 ZnSO4, 0.15 然 CuSO4, 20 然 H3BO3, 0.25 然 Na2MoO4, and 40.5 然 FeNa EDTA) at a pH of 6.1.
	Step 2 Sponge strips were then prepared to secure the plants within the holes of the hydroponic culture boxes. A kitchen sponge (5.5cm x 3cm x 8cm) was cut widthwise with a razor blade into slices (0.5cm) in width. Each of these slices was then cut widthwise into strips (0.5cm) in width. One sponge strip (5.5cm x 0.5cm x 0.5cm) was prepared per plant.
Hydroponic Culture of A. thaliana
	Step 1 At 2-3 weeks following germination, the seedlings were transferred to hydroponic growth conditions. Plants were removed with intact roots from the soil by use of forceps. The forceps were pushed approximately 5 cm into the soil, and then turned upward to uproot the plants from beneath.
	Step 2 Soil was removed from the roots by gentle rinsing of the plant in a tray filled with water. A more thorough cleansing was achieved by a second rinse in a separate tray of water.
	Step 3 Thereafter, a sponge strip was wrapped around the stem of each plant, directly beneath the rosette.
	Step 4 Each plant was then lowered into a hole in the lid of the hydroponic growth box such that the roots were suspended within the box, the sponge secured the plant within the hole, and the rosette remained above the box lid.
	Step 5 The hydroponic culture boxes bearing the A. thaliana plants were then placed in a controlled environment growth chamber. The plants were grown at a 16h, 24慢 day and 8h, 18慢 night regime, under fluorescent and incandescent light with a photon flux density of 170 痠ol/m2s, and at a relative humidity of 65%. Continuous aeration was provided to the growth solution via a 1cm air stone (1/container), rubber tubing threaded through a hole in the hydroponic culture box lid, and an aquarium pump. The hydroponic growth solution was changed two times per week.