Abstract:
:It is generally thought that sedimenting plastids are responsible for gravity sensing in higher plants. We directly tested the model generated by the current statolith hypothesis that the gravity sensing that leads to gravitropism results from an interaction between the plastids and actin microfilaments. We find that the primary roots of rice, corn, and cress undergo normal gravitropism and growth even when exposed to cytochalasin D, a disruptor of actin microfilaments. These results indicate that an interaction between amyloplasts and the actin cytoskeleton is not critical for gravity sensing in higher plants and weaken the current statolith hypothesis.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Staves MP,Wayne R,Leopold ACsubject
Has Abstractpub_date
1997-11-01 00:00:00pages
1530-5issue
11eissn
0002-9122issn
1537-2197journal_volume
84pub_type
杂志文章abstract:PREMISE OF THE STUDY:Evolutionary and biogeographic history, including past environmental change and diversification processes, are likely to have influenced the expansion, migration, and extinction of populations, creating evolutionary legacy effects that influence regional species pools and the composition of communi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1049
更新日期:2018-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Miscanthus, a nonfood plant with high potential as a biofuel, has been used in Europe and the United States. The selection of a cultivar with high biomass, photosynthetic efficiency, and stress resistance from wild populations has become an important issue. New genic microsatellite markers will aid...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100071
更新日期:2011-08-01 00:00:00
abstract::Despite their ecological significance, parasitic plants face more conservation challenges than do autotrophic plants. This is especially true for the groups that include weedy or invasive species such as Cuscuta. While approximately half of the Cuscuta (dodders) species may require conservation measures, the genus as ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800425
更新日期:2009-09-01 00:00:00
abstract:PREMISE OF THE STUDY:The opuntias (nopales, prickly pears) are not only culturally, ecologically, economically, and medicinally important, but are renowned for their taxonomic difficulty due to interspecific hybridization, polyploidy, and morphological variability. Evolutionary relationships in these stem succulents ha...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100375
更新日期:2012-05-01 00:00:00
abstract::The desert moss Syntrichia caninervis exhibits one of the most skewed sex ratios in the plant kingdom, with female individuals far outnumbering male individuals (exceeding 14♀:1♂). The "cost of sex hypothesis" derives from allocational theory and predicts that the sex which is most expensive should be the rarer sex. T...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-11-01 00:00:00
abstract:PREMISE:The genus Arisaema (Araceae) has rapidly diversified in Japan, and multiple species often coexist in the field. Although Japanese Arisaema species hybridize from artificial crossing, hybrid individuals are rare in mixed populations; suggesting the presence of effective pre-pollination barriers. We examined the ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1389
更新日期:2019-12-01 00:00:00
abstract::Incarvillea is a herbaceous and temperate member of Bignoniaceae, previously divided into four subgenera, Niedzwedzkia, Amphicome, Incarvillea, and Pteroscleris. Niedzwedzkia and Amphicome have in the past been treated as independent genera. Different relationships have been proposed for the four subgenera. Here, maxi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.4.625
更新日期:2005-04-01 00:00:00
abstract::The genus Pinguicula is one of the three genera of the carnivorous Lentibulariaceae, comprising approximately 80 species. Phylogeny inference using nucleotide sequences of the chloroplast gene matK and the trnK group II intron, as well as a set of 32 morphological characters revealed five well-supported, major lineage...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.10.1723
更新日期:2005-10-01 00:00:00
abstract::We present here the first molecular phylogeny of tribe Diseae (Orchidoideae: Orchidaceae). Nuclear ribosomal ITS1, 5.8S rDNA, and ITS2 sequences were compared for 30 Diseae, 20 Orchideae, and four Cranichideae and Diurideae outgroups. ITS - rDNA sequences exhibited a transition:transversion ratio of 1.3 and extensive ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract::Axillary meristems play a fundamental role in inflorescence architecture. Maize (Zea mays) inflorescences are highly branched panicles because of the production of multiple types of axillary meristems. We used auxin transport inhibitors to show that auxin transport is required for axillary meristem initiation in the m...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.11.1745
更新日期:2007-11-01 00:00:00
abstract:PREMISE OF THE STUDY:Within the Hypnales-the most derived and species-rich order of pleurocarpous mosses - phylogenies at or below the family level often show poor resolution. In preparation for a phylogeny of the genus Plagiothecium, we wished to identify the DNA markers best suited for evolutionary reconstruction in ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300269
更新日期:2014-04-01 00:00:00
abstract::Many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. Andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. The enneaploid (90 chromosome, 9x) cytotype ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-07-01 00:00:00
abstract::Species of Collinsia and Tonella, the two sister genera of self-compatible annuals that constitute tribe Collinsieae, show extensive variation in floral size and morphology and in patterns of stamen and style elongation during the life of the flower (anthesis). We used a nuclear ribosomal ITS phylogeny, independent co...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.1.37
更新日期:2002-01-01 00:00:00
abstract::We tested the hypothesis that trees growing at high elevations with occasional freezing temperatures have smaller diameter xylem vessels than trees of the same species growing at lower and warmer elevations. The young branch wood of the wide-ranging Hawaiian tree species Metrosideros polymorpha (Myrtaceae) was examine...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.5.709
更新日期:2007-05-01 00:00:00
abstract:PREMISE OF THE STUDY:Microsatellite markers were developed for Petunia integrifolia subsp. depauperata with an intent to clarify taxonomic questions on the P. integrifolia complex, and to identify a purple-flowered parent of P. hybrida. METHODS AND RESULTS:We characterized 11 microsatellite loci by screening primers d...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100178
更新日期:2011-10-01 00:00:00
abstract::Sex ratio and sexual dimorphism in physiology and growth were studied in the dioecious tree Ilex aquifolium at two localities in northern Spain. Genet sex ratio was significantly male biased in one locality but not in the other. However, ramet and flowering ramet sex ratios were male biased at both study sites. Males ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-11-01 00:00:00
abstract:PREMISE OF THE STUDY:Permineralization provides the most faithful known mode of three-dimensional preservation of the morphology and cellular anatomy of fossil plants. Standard optical microscopic documentation of such structures can provide only an approximation of their true three-dimensional form and is incapable of...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300027
更新日期:2013-08-01 00:00:00
abstract::The Strait of Gibraltar is the most important barrier disconnecting the landmasses of Europe and Africa on the western Mediterranean extreme. Carex helodes is a wind-pollinated species endemic to the western Mediterranean. Because molecular and cytogenetic data allow the inference of its evolutionary history, we analy...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.2007342
更新日期:2008-06-01 00:00:00
abstract::The amplified fragment length polymorphism (AFLP) method was used to evaluate genetic diversity and to assess genetic relationships within the section Mentha in order to clarify the taxonomy of several interspecific mint hybrids with molecular markers. To this end, genetic diversity of 62 Mentha accessions from differ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.12.2017
更新日期:2002-12-01 00:00:00
abstract:PREMISE OF THE STUDY:The lycophyte family Selaginellaceae includes approximately 750 herbaceous species worldwide, with the main species richness in the tropics and subtropics. We recently presented a phylogenetic analysis of Selaginellaceae based on DNA sequence data and, with the phylogeny as a framework, the study d...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600288
更新日期:2016-12-01 00:00:00
abstract::Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reporte...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.11.1853
更新日期:2007-11-01 00:00:00
abstract:PREMISE:Root-associated fungi provide a wide range of functions for their host plants, including nutrient provisioning, pathogen protection, and stress alleviation. In so doing, they can markedly influence host-plant structural and physiological traits, although the degree to which these effects vary within particular ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1573
更新日期:2020-12-01 00:00:00
abstract::Evolutionary relationships among representatives of Apiaceae (Umbelliferae) subfamily Apioideae have been inferred from phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer (ITS 1 and ITS 2) and plastid rpoC1 intron sequences. High levels of nucleotide sequence variation preclude the use of the I...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-04-01 00:00:00
abstract::The last decade has witnessed a resurgence in the study of the evolution of plant development, combining investigations in systematics, developmental morphology, molecular developmental genetics, and molecular evolution. The integration of phylogenetic studies, structural analyses of fossil and extant taxa, and molecu...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.10.1726
更新日期:2004-10-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Diversification of floral traits in angiosperms is often attributed to have been driven by adaptations to pollinators. Nevertheless, phylogenetic studies on the relationships among evolutionary changes in floral traits and pollination systems are still limited. We examined the relation...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200359
更新日期:2013-03-01 00:00:00
abstract::We assessed the effects of local environment on survival, growth, and development in six clones (genotypes) of Vallisneria americana grown at five sites in the Huron-Erie Corridor. Detrimental effects of local environment on plant performance (rate of clonal growth, leaf and root production, surface area of leaves and...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::The selective maintenance of gynodioecy depends on the relative fitness of the male-sterile (female) and hermaphroditic morphs. Females may compensate for their loss of male fitness by reallocating resources from male function (pollen production and pollinator attraction) to female function (seeds and fruits), thus in...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-05-01 00:00:00
abstract::Traditional farming communities frequently maintain high levels of agrobiodiversity, so understanding their agricultural practices is a priority for biodiversity conservation. The cultural origin of agave spirits (mezcals) from west-central Mexico is in the southern part of the state of Jalisco where traditional farme...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800176
更新日期:2009-02-01 00:00:00
abstract::• Premise of the study: Wild populations of domesticated species constitute a genetic reservoir and are fundamental to the evolutionary potential of species. Wild papaya (Carica papaya) is a rare, short-lived, gap-colonizing, dioecious tree that persists in the forest by continuous dispersal. Theoretically, these life...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400051
更新日期:2014-07-01 00:00:00
abstract::Individual plants of Asclepias exaltata (Asclepiadaceae) typically express an unusual self-incompatibility system under single-gene control. Hand-pollinations performed in six natural populations detected occasional self-fertile plants. The frequency of self-fertile individuals ranged from 0 to 34.0% and differed sign...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-08-01 00:00:00