Endogenous indole-3-acetic acid and ethylene evolution in tilted Metasequoia glyptostroboides stems in relation to compression-wood formation.
Eight-year-old Metasequoia glyptostroboides seedlings were tilted at a 45 degrees angle to induce compression-wood formation on the lower side of the stems. After 2 weeks of treatment, half of the seedlings were sampled and the remaining half were tilted to the opposite orientation to exchange the upper and lower sides and were kept for 2 more weeks until sampled. Cambium-emitted ethylene was analyzed by gas chromatography with flame-ionization detection. Endogenous indole-3-acetic acid (IAA) was measured by gas chromatography-mass spectrometry. Tracheid production and compression-wood formation were determined by light microscopy. Anatomical studies showed that tracheid production was promoted and compression-wood tracheids always developed on the gravitationally lower side of tilted stems in both the original tilting and the subsequent reverse-tilting periods. These were accompanied by an increase in IAA content in and an accelerated ethylene-evolution rate from the cambial region of the same side.
Du
Sheng
S
Department of Forest Science, Faculty of Agriculture, Tottori University, 4-101 Minami, Koyama, Tottori 680-8553, Japan.
Sugano
Mami
M
Tsushima
Miho
M
Nakamura
Teruko
T
Yamamoto
Fukuju
F
D005075:Biological Evolution; D029779:Cupressaceae / Q000737:chemistry* / Q000502:physiology; D005030:Ethylenes / Q000737:chemistry*; D018522:Gravitropism; D007210:Indoleacetic Acids / Q000737:chemistry*; D018521:Plant Physiological Phenomena; D014934:Wood
D005030:Ethylenes; D007210:Indoleacetic Acids; C030737:indoleacetic acid; C036216:ethylene