Skip to Main Content
Microbial populations and activities in the rhizoplane of rock-weathering desert plants. I. root colonization and weathering of igneous rocks.Author(s): M.E. Puente; Y. Bashan; C.Y. Li; V.K. Lebsky
Source: Plant Biology. 6: 629-642
Publication Series: Scientific Journal (JRNL)
PDF: View PDF (2.4 MB)
DescriptionDense layers of bacteria and fungi in the rhizoplane of three species of cactus (Pachycereus pringlei, Stenocereus thurberi, Opuntia cholla) and a wild fig tree (Ficus palmeri) growing in rocks devoid of soil were revealed by bright-field and fluorescence microscopy and field emission scanning electron microscopy. These desert plants are responsible for rock weathering in an ancient lava flow at La Purisima-San Isidro and in sedimentary rock in the Sierra de La Paz, both in Baja California Sur, Mexico. The dominant bacterial groups colonizing the rhizoplane were fluorescent pseudomonads and bacilli. Seven of these bacterial species were identified by the 165 rRNA molecular method. Unidentified fungal and actimomycete species were also present. Some of the root-colonizing microorganisms fixed in vitro N2, produced volatile and non-volatile organic acids that subsequently reduced the pH of the rock medium in which the bacteria grew, and significantly dissolved insoluble phosphates, extrusive igneous rock, marble, and limestone. The bacteria were able to release significant amounts of useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn from the rocks and were thermo-tolerant, halo-tolerant, and drought-tolerant. The microbial community survived in the rhizoplane of cacti during the annual 10-month dry season. This study indicates that rhizoplane bacteria on cacti roots in rock may be involved in chemical weathering in hot, subtropical deserts.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationPuente, M.E.; Bashan, Y.; Li, C.Y.; Lebsky, V.K. 2004. Microbial populations and activities in the rhizoplane of rock-weathering desert plants. I. root colonization and weathering of igneous rocks. Plant Biology. 6: 629-642
KeywordsBacillus, cactus, cardon, cholla, desert, Ficus, fig tree, fluorescent psuedomonads, lava degradation, nitrogen fixation, Opuntia, Pachycereus, phosphate solubilization, rock weathering, soil formation, Stenocereus
- Endophytic bacteria in cacti seeds can improve the development of cactus seedlings.
- Changes in microbial community structure following herbicide (glyphosate) additions to forest soils
- Bacterial associations with decaying wood : a review
XML: View XML