Jasmonic acid, protein phosphatase inhibitor, metals and UV-irradiation increased momilactone A and B concentrations in the moss Hypnum plumaeforme

Abstract

Momilactone A and B have been found only in rice and the moss, Hypnum plumaeforme, although both plants are taxonomically quite distinct. The endogenous concentrations of momilactone A and B in H. plumaeforme were 58.7 and 24.3 microg/g dry weight, respectively. UV-irradiation increased the concentrations of momilactone A and B. The concentrations of momilactone A and B, respectively, became 14- and 15-fold greater than those of non-UV-irradiated control. CuCl2 and FeCl2 (1 mmol/L) treatments also increased momilactone A and B concentrations by 2.7- to 6.1-fold and 2.9- to 6.3-fold, respectively. In addition, the protein phosphatase inhibitor, cantharidin, and jasmonic acid increased momilactone A and B concentrations in H. plumaeforme. Cantharidin acts as an elicitor and jasmonic acid is an important signaling molecule regulating inducible defense genes against the pathogen infection. Momilactone A and B, respectively, were increased 12- and 11-fold by 200 micromol/L cantharidin, and 14- and 15-fold by 100 micromol/L jasmonic acid compared with non-treated controls. As momilactone A and B are phytoalexins, these compounds may play an important role in defense responses against biotic and abiotic stress conditions in H. plumaeforme.

Secretion of momilactone A and B by the mossHypnum plumaeforme

“…The endogenous concentration of momilactone A and B in H. plumaeforme was 58.7 and 23.4 μg g -1 dry weight, respectively. 4 Thus, the secretion levels of momilactone A and B, respectively, were 6.8 and 27% of momilactone A and B concentrations in H. plumaeforme. Therefore, although the endogenous concentration of momilactone A in H. plumaeforme was greater than that of momilactone B, the secretion level of momilactone B was much greater than that of momilactone A, which suggests that momilactone B may be selectively secreted into the medium than momilactone A.…”

“…The concentrations of momilactone A and B in UV-irradiated H. plumaeforme were 786 and 348 μg g -1 dry weight, respectively. 4 Jasmonic acid and cantharidin increased the secretion of momilactone A and B by H. plumaeforme (Table 1). The concentrations of momilactone A and B, respectively, were 796 and 345 μg g -1 dry weight in 100 μM jasmonic acid-treated H. plumaeforme, and 661 and 282 μg g -1 dry weight in 200 μM cantharidin-treated H. plumaeforme.…”

“…10 H. plumaeforme was transplanted on MS growth medium and grown at 25°C with a 12-h photoperiod for 5 days as described previously. 4 During the incubation, additional UV-irradiation (80 min par day, UV, emission peak 253 nm; 10 μmol m -1 s -1 at plant level) was made. Momilactone A and B concentrations in the medium were then determined as the secretion levels by H. plumaeforme.…”

“…[1][2][3][4] Momilactone A and B in rice plants are known to be synthesized as a part of defensive responses and exhibit antibacterial and antifungal activities. [5][6][7] Rice plants were also found to secrete momilactone A and B from their roots into the rhizosphere and exhibit alleloapthic activities against weed plants.…”

Discovery, Biosynthesis and Stress-Related Accumulation of Dolabradiene-Derived Defenses in Maize

“…Because of their agronomic importance as two of the world's major food crops, maize (Zea mays) and rice (Oryza sativa) have been studied extensively for their terpenoid-based defense systems (Degenhardt, 2009;Schmelz et al, 2014). In rice, a suite of momilactone, oryzalexin, and phytocassane diterpenoids confer defense against several major pathogens, such as rice blast (Magnaporthe oryzae; Peters, 2006;Kato-Noguchi and Kobayashi, 2009;Toyomasu et al, 2014). As components of rice root exudates, momilactones also can exhibit allelopathic activity, suppressing the development of neighboring plants of other species (Kato-Noguchi and Peters, 2013).…”