Norepinephrine induces flower-inducing substance
In human, norepinephrine (NE) acts directly on coronary vessels to cause
vasodilation and improve blood supply to the heart (Papadopoulos et al.,
2010). The noradrenergic system serves multiple brain functions
including arousal, attention, mood, learning, memory and stress response
(Sofuoglu, & Sewell, 2009). Moreover, more evidences have even shown
the relationship between neuroprotective disease and norepinephrine
(Moret, & Briley, 2011).
High levels of allegedly animal hormone, epinephrine and norepinephrine,
have been also detected in peyote (Kulma, & Szopa, 2007). Lower in
oranges, apples, tomatoes, eggplants, spinach, beans, and peas (Feldman,
Lee, & Castleberry, 1987). And they play in corresponding regulation of
plant physiology. Flowering is a vital physiological phenomenon of
plants. Flower-inducing substance (FIS) could be induced by many
factors. Studies have shown that NE could interact with FIS to induce
flowering in plant. Lemna paucicostata which had been immersed in
NE solution (2 mM) had strong FIS activity (Yokoyama et al., 2000). The
active component in flower-inducing substance is identified as tyrosine,
which means FIS is derived from NE upon contact with the lemna(Yamaguchi, 2001). However, the functional and regulatory mechanisms of
NE corresponding with FIS remain to be elucidated.
Furthermore, NE and epinephrine have similar physiological effects in
plants due to similar chemical structures (Kulma, & Szopa, 2007). NE in
50 mM and epinephrine in 100 mM are demonstrated to stimulate ethylene
synthesis in sugarbeet (Elstner et al., 1976). The same effects were
observed in orchardgrass and potato cell culture (Kuklin, & Conger,
1995; Dai, Michaels, & Flores, 1993). There may be an interaction
between endogenous plant hormones and them. Moreover, norepinephrine is
believed to be a precursor for secondary alkaloids, such as berberastine
(Szopa, Wilczyński, Fiehn, Wenczel, & Willmitzer, 2001). However, most
of these studies were done decades ago. Further confirmation is
necessary with more convincing methods developed recently (Kulma, &
Szopa, 2007).