Analysis of Magnetic Gradients to Study Gravitropism1. Issue 1 (1st January 2013)

• Record Type: Journal Article
• Authors: Hasenstein, Karl H.; John, Susan; Scherp, Peter; Povinelli, Daniel; Mopper, Susan
• Is Part Of: American journal of botany. Volume 100:Issue 1(2013)
• Page Start: 249
• Page End: 255
• Publication Date: 2013-01-01
• Subjects: diamagnetism -- gravisensing -- gravitropism -- high‐gradient magnetic field -- HGMF -- Solanum tuberosum -- starch -- Triticum aestivum -- Zea mays; Botany -- Periodicals; Botany; Electronic journals; Periodicals; 580
• DOI: 10.3732/ajb.1200304
• Languages: English
• ISSNs: 0002-9122

Abstract

Abstract : Premise of the study: Gravitropism typically is generated by dense particles that respond to gravity. Experimental stimulation by high‐gradient magnetic fields provides a new approach to selectively manipulate the gravisensing system. Methods: The movement of corn, wheat, and potato starch grains in suspension was examined with videomicroscopy during parabolic flights that generated 20 to 25 s of weightlessness. During weightlessness, a magnetic gradient was generated by inserting a wedge into a uniform, external magnetic field that caused repulsion of starch grains. The resultant velocity of movement was compared with the velocity of sedimentation under 1 g conditions. Results: The high‐gradient magnetic fields repelled the starch grains and generated a force of at least 0.6 g . Different wedge shapes significantly affected starch velocity and directionality of movement. Conclusions: Magnetic gradients are able to move diamagnetic compounds under weightless or microgravity conditions and serve as directional stimulus during seed germination in low‐gravity environments. Further work can determine whether gravity sensing is based on force or contact between amyloplasts and statocyte membrane system.