The Role of Spore Germination and Gametophyte Development in Habitat Selection: Temperature Responses in Certain Temperature and Tropical Ferns

1980 ◽  
Vol 107 (1) ◽  
pp. 57 ◽  
Author(s):  
Thomas R. Warne ◽  
Robert M. Lloyd
2006 ◽  
Vol 189 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Venkata Ramana Vepachedu ◽  
Peter Setlow

ABSTRACT The release of dipicolinic acid (DPA) during the germination of Bacillus subtilis spores by the cationic surfactant dodecylamine exhibited a pH optimum of ∼9 and a temperature optimum of 60°C. DPA release during dodecylamine germination of B. subtilis spores with fourfold-elevated levels of the SpoVA proteins that have been suggested to be involved in the release of DPA during nutrient germination was about fourfold faster than DPA release during dodecylamine germination of wild-type spores and was inhibited by HgCl2. Spores carrying temperature-sensitive mutants in the spoVA operon were also temperature sensitive in DPA release during dodecylamine germination as well as in lysozyme germination of decoated spores. In addition to DPA, dodecylamine triggered the release of amounts of Ca2+ almost equivalent to those of DPA, and at least one other abundant spore small molecule, glutamic acid, was released in parallel with Ca2+ and DPA. These data indicate that (i) dodecylamine triggers spore germination by opening a channel in the inner membrane for Ca2+-DPA and other small molecules, (ii) this channel is composed at least in part of proteins, and (iii) SpoVA proteins are involved in the release of Ca2+-DPA and other small molecules during spore germination, perhaps by being a part of a channel in the spore's inner membrane.


2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Yupi ISNAINI ◽  
Titien Ngatinem Praptosuwiryo

Abstract. Isnaini Y, Praptosuwiryo TNg. 2020. In vitro spore germination and early gametophyte development of Cibotium barometz (L.) J. Sm. in different media. Biodiversitas 21: 5373-5381. Cibotium barometz (L.) J. Sm. is known as the golden chicken fern and included in Appendix II of CITES. It is an important export commodity for traditional and modern medicine. Globally, populations of this species are under significant pressure due to overexploitation in the wild. In vitro culture is one of the technologies used for ex-situ propagation and conservation of rare and endangered ferns and lycophytes. This study’s objectives were: (i) to observe in vitro spore germination and early gametophyte development of C. barometz, and (ii) to determine the best culture medium for rapid spore germination and early development of the gametophytes. The sterilized spores were sown in half-strength Murashige & Skoog (½MS) basal medium supplemented with combinations of 6-Benzylaminopurine (BAP) and α-Naphthalene acetic acid (NAA). A factorial combination of four BAP concentrations (0, 2, 4, and 6 mg L-1) with four concentrations of NAA (0; 0.01; 0.03 and 0.05 mg L-1) created 16 treatments replicated in a Completely Randomized Design. Spore germination of C. barometz was observed to be Vittaria-type, and its prothallial development was Drynaria-type. Spore germination started 7-14 days after sowing. Young heart-shape gametophytes consisting of 110-240 cells were formed in 45-61 days after sowing. The two best spore culture media for rapid spore germination and development of C. barometz gametophytes were ½ MS with or without 2 mg L-1 BAP.


2007 ◽  
Vol 70 (9) ◽  
pp. 2168-2171
Author(s):  
JONG-KYUNG LEE ◽  
SARA MOVAHEDI ◽  
STEPHEN E. HARDING ◽  
BERNARD M. MACKEY ◽  
WILLIAM M. WAITES

To find the range of pressure required for effective high-pressure inactivation of bacterial spores and to investigate the role of α/β-type small, acid-soluble proteins (SASP) in spores under pressure treatment, mild heat was combined with pressure (room temperature to 65°C and 100 to 500 MPa) and applied to wild-type and SASP-α−/β− Bacillus subtilis spores. On the one hand, more than 4 log units of wild-type spores were reduced after pressurization at 100 to 500 MPa and 65°C. On the other hand, the number of surviving mutant spores decreased by 2 log units at 100 MPa and by more than 5 log units at 500 MPa. At 500 MPa and 65°C, both wild-type and mutant spore survivor counts were reduced by 5 log units. Interestingly, pressures of 100, 200, and 300 MPa at 65°C inactivated wild-type SASP-α+/β+ spores more than mutant SASP-α−/β− spores, and this was attributed to less pressure-induced germination in SASP-α−/β− spores than in wild-type SASP-α+/β+ spores. However, there was no difference in the pressure resistance between SASP-α+/β+ and SASP-α−/β− spores at 100 MPa and ambient temperature (approximately 22°C) for 30 min. A combination of high pressure and high temperature is very effective for inducing spore germination, and then inactivation of the germinated spore occurs because of the heat treatment. This study showed that α/β-type SASP play a role in spore inactivation by increasing spore germination under 100 to 300 MPa at high temperature.


2007 ◽  
Vol 189 (12) ◽  
pp. 4375-4383 ◽  
Author(s):  
Graham Christie ◽  
Christopher R. Lowe

ABSTRACT Spores of Bacillus megaterium QM B1551 germinate in response to a number of trigger compounds, including glucose, proline, leucine, and inorganic salts. An approximate 6-kb region of the 165-kb plasmid was found to harbor a tricistronic receptor operon, gerU, and a monocistronic receptor component, gerVB. The gerU operon was observed to complement the germination response in plasmidless strain PV361 to glucose and leucine, with KBr acting as a cogerminant. Proline recognition is conferred by the monocistronic gerVB gene, the presence of which also improves the germination response to other single-trigger compounds. A chimeric receptor, GerU*, demonstrates interchangeability between receptor components and provides evidence that it is the B protein of the receptor that determines germinant specificity. Introduction of the gerU/gerVB gene cluster to B. megaterium KM extends the range of germinants recognized by this strain to include glucose, proline, and KBr in addition to alanine and leucine. A chromosomally encoded receptor, GerA, the B component of which is predicted to be truncated, was found to be functionally redundant. Similarly, the plasmid-borne antiporter gene, grmA, identified previously as being essential for germination in QM B1551, did not complement the germination defect in the plasmidless variant PV361. Wild-type spores carrying an insertion-deletion mutation in this cistron germinated normally; thus, the role of GrmA in spore germination needs to be reevaluated in this species.


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