The inhibitory effect of tropolone and hinokitiol on the mycelium growth of Phoma narcissi in vitro

Tropolone and hinokitiol (β-thujaplicin) that are present in heartwood of several Cupressaceae trees are known for their antibacterial, antifungal and insecticidal properties. In the present studies it was showed that tropolone and hinokitiol greatly inhibited in vitro, on PDA medium, the mycelium growth of Phoma narcissi, a pathogen of Hippeastrum and other species of family Amaryllidaceae. Total inhibition of the mycelium growth of Phoma narcissi took place at a tropolone concentration of 6.0 µg·cm-3 and at a hinokitiol concentration of 50.0 µg·cm-3. Fungicidal doses of tropolone and hinokitiol for the mycelium growth of Phoma narcissi were also documented. The results presented in this paper are discussed with data available in literature on the antifungal action of tropolone and hinokitiol on other species of pathogenic fungi

THE EFFECT OF SOME PLANT GROWTH REGULATORS AND THEIR COMBINATION WITH METHYL JASMONATE ON ANTHOCYANIN FORMATION IN ROOTS OF KALANCHOE BLOSSFELDIANA

ABSTRACT In this study, we investigated the effect of plant growth regulators (PGRs) -auxins, gibberellin, cytokinin, abscisic acid, brassinosteroid, ethylene and their interaction with methyl jasmonate (JA-Me) applied to roots of the whole plants Kalanchoe blossfeldiana on the accumulation of anthocyanins in roots. The highest stimulation of anthocyanins synthesis was stated with application of JA-Me alone. In response to treatments with the other tested PGRs, the content of anthocyanins in roots of a whole plant was different depending on the concentration of the PGR when being applied alone or together with JA-Me. Auxin, indole-3-acetic acid (IAA) at a concentration of 50 mg·L -1 , indole-3-butyric acid (IBA) at 5 mg·L -1 and abscisic acid (ABA) at 10 mg·L -1 induced anthocyanin accumulation with approximately 60-115% compared to the control while 24-epibrassinolid (epiBL), gibberellic acid (GA3) and 6-benzylaminopurine (BAP) had no effect on the anthocyanin accumulation. The simultaneous administration of the PGRs with JA-Me usually resulted in the accumulation of anthocyanins in roots in a manner similar to that caused by JA-Me. PGRs applied to isolated roots did not stimulate anthocyanin accumulation, except for the combination of JA-Me with 50 mg·L -1 IAA. The results indicate that in K. blossfeldiana, the aboveground parts of the plant play an important role in the biosynthesis of anthocyanins in roots

Methyl Jasmonate Induces Gummosis in Plants

Gum in plants is induced by environmental stress factors such as pathogens infection, insect attack, mechanical and chemical injuries, water stress and others. All these factors are considered to act via ethylene produced in plant tissues. Recently we have also shown that jasmonates, a new group of plant hormones, induced gummosis in tulip, peach, apricot, plum and cherry. This review paper describes physiological roles of jasmonates in gum induction and/or production in these plants and chemical compositions of gums. A possible mode of action of jasmonates in the process of gummosis will also be discussed in point of the interaction with ethylene

Differential effects of N-1-naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) on auxin control of swelling of the shoots of Bryophyllum calycinum Salisb.

The effects of N-1-naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic acid (TIBA) on the swelling of the stem in intact and decapitated plants of Bryophyllum calycinum in relation to the interaction with auxin, indole-3-acetic acid (IAA), are described. NPA induced conspicuous local internode swelling only in the area of its application in intact plants and in the decapitated internode in the case of simultaneous application of IAA on the top of the internode. By contrast, TIBA applied to an internode of intact plants induced swelling along the entire internode above the treatment area, and similar results were obtained in the decapitated internode when TIBA was applied in the middle of the internode and IAA was applied onto the top of the internode. The differential effect of NPA and TIBA on stem swelling in B. calycinum is discussed in relation to their differential mode of action on auxin transport

Differential effects of auxin polar transport inhibitors on rooting in some Crassulaceae species

Effects of auxin polar transport inhibitors, 2,3,5-triio-dobenzoic acid (TIBA), 1-N-naphthylphthalamic acid (NPA) and methyl 2-chloro-9-hydroxyfluorene-9-carboxylate (morphactin IT 3456), as a lanolin paste, on root formation in cuttings of some species of Crassulaceae, such as Bryophyllum daigremontianum, B. calycinum, Kalanchoe blossfeldiana and K. tubiflora, were studied. Cuttings of these plants were easily rooted in water without any treatment. TIBA and morphactin IT 3456 completely inhibited root formation in the cuttings of these plants but NPA did not when these inhibitors were applied around the stem below the leaves. When TIBA and morphactin were applied around the stem near the top, but leaves were present below the treatment, the root formation was observed in B. calycinum and K. blossfeldiana but in a smaller degree than in control cuttings. These results strongly suggest that endogenous auxin is required for root formation in cuttings of Crassulaceae plants. The differential mode of action of NPA is discussed together with its effect on auxin polar transport