X-ray diffraction and small-angle neutron scattering were used to identify the naturally occurring hormone auxin in Madeira vine. Two kinds of auxins belonging to indole-3-acetic acid (IAA, C 10 H 9 NO 2 ) and 4-chloroindole-3-acetic acid (4-Cl-IAA, C 10 H 8 ClNO 2 ) have been found. The appearance of well-defined x-ray diffraction peaks from the IAA as well as from the 4-Cl-IAA structures shows that the IAA and 4-Cl-IAA molecules that are produced at the shoot apex crystallize into periodic arrangements, rather than stay in molecular forms, upon transport downward through in stem. Small angle neutron scattering spectra reveal a progressive increase in the length of crystallized IAA and 4-Cl-IAA on transported downward from the shoot apex to the stem, reaching 59 nm in length in the area 8-9 cm below the shoot apex. A portion of IAA loses their carboxyl group COOH becoming inactive in stimulating cell growth, which slows down the growth in an aged stem.
The low-temperature nuclear-orientation technique was applied to two single crystals of Fe1.67Ge, one doped with traces of 54Mn and the other with traces of 60Co, and the magnitudes of the effective hyperfine fields were deduced at these two nuclear sites. An estimate of the spin-lattice relaxation time constant was also found for the MnFe1.67Ge and CoFe1.67Ge systems.
Madeira vine (MV) grows 30 times faster after encountering a support. In vivo x-ray diffraction made on live MV stems revel the appearance of crystallized IAA (C10H9NO2), 4-Cl-IAA (C10H8ClNO2) and 6-Cl-IAA (C10H8ClNO2) in the stems. Small angle neutron scattering spectra of the IAA extracted from MVs stem reveal a progressive increase in the size of crystallized IAA transported downward from the apex of the shoots. High resolution X-ray diffractions made on the extracted IAA reveal significantly larger amounts of 4-Cl-IAA and 6-Cl-IAA in the climbing MVs than in the swaying around MVs. The gas chromatography-mass spectrometry spectra reveal the production of 9% more IAA and 90% more 4-Cl-IAA+6-Cl-IAA at the apexes of climbing MVs than swaying MVs. More 4-Cl-IAA+6-Cl-IAA were transported to the contact-free side than to the contact side of the vine. In vivo neutron tomography of naturally climbing MVs reveals a substantially higher H+ concentration in the contact-free parts than in the contact parts. The absorption spectra also reveal more expansin in the contact-free parts than in the contact parts. These results provide a view, at the molecular level, of what triggers the faster and differential growths in MVs in response to touching a support.
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