Plants use gravity as a guide for growth and development. Gravitropism, a gravity-directed growth process, directs upward shoot movement for efficient photosynthesis and gaseous exchange. In addition, it also directs downward growth of roots in soil, for assimilation of water and nutrients required for growth and development. Using time lapse video imaging this process can be efficiently studied in a real time scale. The analysis of the response under different conditions can help to unravel the mechanisms regulating gravitropism.
Blue light (An alternate light source can also be used) for gravitropic analysis was obtained from blue LEDs (Light Emitting diodes, λmax 470 nm, Kwality Photonics). Photon fluence of light was measured with a light meter fitted with a Quantum sensor (Skye Instruments, UK).
Spectrum of the blue light was measured using spectroradiometer purchased from International Light Technologies (model: RPS900W)
Quickcam Pro 3000 or 4000 (Logitech) or any other suitable webcam for recording the response
Germination paper (locally purchased) or blotting paper or Whatman paper
Square germination boxes (dimension 10 x10 x 6 cm, Laxbro) / or square petriplates
Square petriplate (dimension 12x12x2 cm, Genaxy, model: GEN-PTD-130SQ)
Forceps from Pro’Kit® 1PK-125T (dimension 12 x1 x 4 cm)
Readers should cite both the Bio-protocol article and the original research article where this protocol was used:
Sharma, S., Tyagi, K., Sreelakshmi, Y. and Sharma, R. (2015). Gravitropic Analysis of Tomato Seedlings using Time Lapse Video Imaging. Bio-protocol 5(7): e1443. DOI: 10.21769/BioProtoc.1443.