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Bioelectromagnetism

FIGURE 5.9 Plant lipid responses to reduced magnetic feld.

and seed-set developmental stages. Variations in SA composition were correlated to the diferential

expression of several Arabidopsis 3-ketoacyl-CoAsynthase (KCS) genes, including KCS1, KCS5, KCS6,

KCS8, and KCS12, a lipid transfer protein (LTPG1), and a lipase (LIP1). Ionomic analysis showed also

a signifcant variation in some micronutrients (Fe, Co, Mn, and Ni) and macronutrients (Mg, K, and

Ca) during the plant development of plants exposed to NNMF (Islam et al., 2020b). Figure 5.9 sum­

marizes the efects of GMF reduction on lipid metabolism. Tese results and the results shown above

indicate that A. thaliana responds to variations of the GMF which are perceived as is typical of abiotic

stress responses.

Te GMF regulates genes in both shoot and roots, suggesting that both organs can sense the GMF.

However, 49% of the genes are regulated in a reverse direction in these organs, meaning that the resident

signaling networks defne the up- or downregulation of specifc genes. Te set of GMF-regulated genes

strongly overlaps with various stress-responsive genes, implicating the involvement of one or more com­

mon signals, such as reactive oxygen species, in these responses. Te biphasic dose response of GMF-

responsive genes indicates a hormetic response of plants to the GMF that can sense and respond to the

GMF using the signaling networks involved in stress responses (Paponov et al., 2021). It is interesting to

note that (1) roots and shoot have diferent gene expression responses to the GMF, as almost 50% of the

regulated genes were triggered in a reverse manner; (2) the efects of the GMF are related to activation

of stress-responsive genes; and (3) the majority of identifed GMF-responsive genes show biphasic dose-

dependent expression, indicating a hormetic response of plants to MFs (Figure 5.10). Te diferential

regulation of genes in roots and shoots might also be related to the diferent roles of plastids in the roots

and shoots. Indeed, GO analysis has shown that genes related to chloroplast functions were overrepre­

sented among the genes regulated by the GMF, indicating that diferent functions of plastids in roots

and shoots can contribute to the diferential responses of roots and shoots to the GMF. Tese observa­

tions support recent fndings that chloroplasts are one of the main targets of MF efects in Arabidopsis

(Jin et al., 2019). One important consideration is that the function of chloroplasts is related to the cellular

redox status (Baier and Dietz, 2005), which can induce ROS imbalances and modulate the expression

of genes induced by diferent stresses. Indeed, GO analysis has shown that variations in MFs afect the

regulation of stress-responsive genes. Moreover, early gene modulations by MFs are associated with

redox responses, implying that rapid rates of redox reactions, triggered by an MF, alter the metabolism

of free radicals and ROS.