Suppression of Arabidopsis flowering by near‐null magnetic field is mediated by auxin

Abstract

We previously found that flowering of Arabidopsis was suppressed by near-null magnetic field, which was related to cryptochrome. Auxin plays an important role in Arabidopsis flowering. To test whether auxin is involved in the suppression of Arabidopsis flowering by near-null magnetic field, we detected auxin level and expressions of auxin transport and signaling genes in wild-type Arabidopsis plants and cryptochrome double mutant, cry1/cry2, grown in near-null magnetic field. We found that indole-3-acetic acid (IAA) level in roots of wild-type plants in near-null magnetic field was significantly increased compared with the local geomagnetic field control, while IAA level in rosettes of 33-day-old wild-type plants in near-null magnetic field was significantly lower than the control. Expressions of three auxin transporter genes, PIN1, PIN3, and PIN7, in wild-type plants were upregulated by near-null magnetic field. Transcript levels of transcriptional repressor genes, IAA1, IAA5, IAA6, IAA16, and IAA19, were significantly higher in wild-type plants in near-null magnetic field than in control plants. However, IAA level and expressions of all the detected genes in cry1/cry2 mutants in near-null magnetic field were similar to controls. Our results suggest that near-null magnetic field affects the distribution of auxin in Arabidopsis by transcriptional upregulation of auxin transporter genes, and that change in distribution of auxin and increased expressions of transcriptional repressor genes result in delay of flowering in Arabidopsis in near-null magnetic field, which are mediated by cryptochrome. Bioelectromagnetics. 39:15-24, 2018.

Gibberellins are involved in effect of near‐null magnetic field on Arabidopsis flowering

“…We previously found that flowering of Arabidopsis in near-null magnetic field was delayed, which was blue light dependent, suggesting that cryptochrome is involved in the effect of near-null magnetic field on Arabidopsis flowering [Xu et al, 2012[Xu et al, , 2015. We also found that phosphorylation and dephosphorylation of cryptochrome were affected by near-null magnetic field, implying that function of cryptochrome can be modified by near-null magnetic field [Xu et al, 2014].…”

“…Cryptochrome plays a major role in photoperiodic flowering of Arabidopsis [Guo et al, ; Mockler et al, , ; Lin, ]. We previously found that flowering of Arabidopsis was suppressed by near‐null magnetic field, which was mediated by functional modification of cryptochrome [Xu et al, , , , ]. We then wanted to disclose the physiological mechanism of the effect of near‐null magnetic field on Arabidopsis flowering, and the relation between physiological changes and cryptochrome in Arabidopsis.…”

Decline of cell viability and mitochondrial activity in mouse skeletal muscle cell in a hypomagnetic field

“…According to the radical pair theory, an external magnetic field affects chemical reactions by alternating electron spin state of a weakly coupled radical pair, which is produced as an intermediate of the electron transport chain reactions [Zhang et al, ]. This has been proved in plant, drosophila and migrating birds [Gegear et al, ; Zhang et al, ; Xu et al, ]. Foley et al [] showed that human cryptochrome could restore the magnetosensation of cry‐knock out Drosophils, which suggest that mammalian also share a similar radical pair reaction‐based magnetosensation.…”

The Geomagnetic Field Is a Contributing Factor for an Efficient Iron Uptake in Arabidopsis thaliana

“…In plants, recent reports revealed that variation of MF intensity affects photoreceptor activity (Agliassa et al, 2018b) and light-dependent processes such as leaf movement, stomatal conductance, and chlorophyll content (Galland and Pazur, 2005;Maffei, 2014). Furthermore, changes in the hormone levels, for instance, auxin and gibberellin, as well as a delay in flowering time have also been observed under near null MF (NNMF) conditions (Xu et al, 2012(Xu et al, , 2017(Xu et al, , 2018Agliassa et al, 2018a). Such delayed transition to flowering under NNMF is likely involved in the Angiosperms speciation during GMF reversals (Maffei, 2014;Occhipinti et al, 2014;Bertea et al, 2015), suggesting a possible contribution of the GMF magnitude on plant evolution.…”