摘要:

Leaves from 12 legume species representing two subtribes were examined by various techniques for the presence of vegetative storage proteins (VSPs) similar to the 27, 29, and 94 kD VSPs of soybean. Polyacrylamide gel electrophoresis (PAGE) of leaf protein followed by western immunoblotting using antibody that recognizes soybean VSP94, a lipoxygenase, demonstrated that this protein is present in six of the nine species tested. Blotting with antibody to soybean VSP27/29, which are glycoproteins, gave labelling in seven species and glycoprotein affino‐blots showed that glycosylated proteins ranging around 27 to 29 kD were present in all nine species examined. Immunocytochemical localization studies of eight species demonstrated that proteins antigenically similar to VSP94 and VSP27/29 are specifically accumulated in the vacuole of paraveinal mesophyll (PVM) cells. They were not detectable at significant levels in other mesophyll cells using this technique. Comparisons of protein compositions of isolated PVM and mesophyll protoplasts from seven species further confirmed the specialized nature of the PVM. VSP94 and proteins ranging from 25 to 35 kD molecular mass were the major proteins of PVM of all but one species while Rubisco was quite low in amount compared to mesophyll protoplasts. The results show that VSP synthesis and accumulation is a general feature of legume leaves containing a PVM layer and indicate that the PVM plays a specialized role in nitrogen metabolism and partitioning in these species.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13867.x

出版商:Wiley    

年代:1996

数据来源: WILEY

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb15763.x

出版商:Wiley    

年代:1996

数据来源: WILEY

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb15764.x

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

Seed dormancy characteristics ofSpartina alterniflorawere delineated previously by Plyler and Carrick (American Journal of Botany, vol. 80, pp. 752–756, 1993). This study was undertaken in order to determine whether or not the dormancy characteristics ofS. patensare similar. As in the previous study, the site of a dormancy mechanism was determined by assessing the germinability of surgically altered dormant seeds. Likewise, the effects of three growth‐regulating substances (abscisic acid, fusicoccin, and gibberellic acid), prechilling, and light were studied by assessing the germinability of appropriately treated dormant seeds. Surgical injury to the endosperm, and to a lesser extent the scutellum, produced significant germination inS. patens, whereas only injury to the scutellum produced germination inS. alterniflora. Exogenously applied abscisic acid was highly effective in maintaining dormancy in injured seeds of both species. Gibberellic acid and fusicoccin were ineffective in promoting germination inS. patens, but fusicoccin was highly effective in breaking dormancy in 5.alterniflora.Prechilling was effective in breaking dormancy inS. patensbut not inS. alterniflora.InS. patens, treatments that broke dormancy were only successful when seeds were exposed to light during the germination period. It is concluded that the dissimilarities in the dormancy mechanisms may be manifestations of the different environmental adaptations these closely related species display.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13868.x

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

The morphology and leaf anatomy, water relations, gas exchange, and growth characteristics ofBetula papyriferaseedlings grown in a greenhouse representing three ploidy levels (diploids, pentaploids, and hexaploids) have been compared in an effort to understand the role of polyploidy in habitat differentiation and adaptation to water deficit. The polyploids are more tolerant of water deficit than their diploid relatives. The polyploids have fewer stomata per unit area and smaller stomatal indices than the diploids. They also have thicker upper and lower epidermis and more pubescence, which tend to reduce water loss. The polyploids have lower osmotic potential at saturation (p.sat) than corresponding diploids, suggesting they are more able to maintain turgor in the case of low tissue water potential than the diploids. The photosynthesis of the diploids is more sensitive to water deficit. A 2‐hr artificial water stress treatment caused complete cessation of photosynthesis in the diploids. They are more drought‐avoiding than the polyploids as evidenced by closing their stomata to limit water loss at a relatively higher tissue water potential (‐1.425 MPa). The pentaploids and hexaploids maintained, although to a small extent, photosynthesis when their tissue water potentials dropped to ‐1.86 MPa and ‐2.07 MPa, respectively.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13869.x

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

Genetic diversity in three genera of perennial plants found in the sand pine, oak scrub in peninsular Florida was examined by allozyme electrophoresis. These plants vary greatly in terms of geographic range, population size, pollination ecology, and seed dispersal mechanisms.Ceratiola ericoides(Empetraceae) is a shrub that occurs throughout scrub and other sandy habitats in Florida and neighboring states. In contrast,Eryngium cuneifolium(Apiaceae) is a Federally endangered herbaceous perennial, limited to the southern end of the Lake Wales Ridge, site of a proposed National Wildlife Refuge that would be the first designed primarily to protect plant diversity. Four species of endangered woody perennialDicerandra(Labiatae) are part of a monophyletic group endemic to Florida sand pine scrubs;Dicerandra frutescensandD. christmaniiare found on the southern end of the Lake Wales ridge,D. cornutissimais found in north‐central Florida, andD. immaculataoccurs in a small area along Florida's Atlantic coast. Allozyme electrophoresis of 17 loci forC. ericoidesindicated that 64.7% of the loci were polymorphic (Ps), that there were 2.55 alleles per polymorphic locus (APs), and that the mean gene diversity (Hes) was 0.141. The proportion of genetic diversity among the four populations (GST) was 0.059. For the 31 loci analyzed inE. cuneifolium, Pswas 32.3%,APSwas 2.1, andHeswas 0.104.GSTwas 0.106. The woodyDicerandraspecies complex (four species) was analyzed for 17 loci.Pswas 64.7%,APswas 3.1, and mean gene diversity was 0.219. The meanGSTvalue across the species complex was 0.137. Taken together these results suggest that considerable genetic variation is still present in the relict populations of the rare scrub taxa (EryngiumandDicerandra), but that to preserve current levels of genetic variation will require protecting areas in each of several different scrub regions along a 350‐km stretch of peninsular Florida.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13870.x

出版商:Wiley    

年代:1996

数据来源: WILEY

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb15765.x

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

The ultrastructure, morphology, and histology of somatic embryogenesis in pearl millet (Pennisetum glaucum) were examined using light and electron microscopic techniques. Somatic embryogenesis was initiated from zygotic embryo explants cultured 8 d after pollination. Formation of a ridge of tissue began 3–4 d after culture (DAC) by divisions in the epidermal and subepidermal cells of the scutellum. Ridge formation was accompanied by a decrease in vacuoles, lipid bodies, and cell size, and an increase in endoplasmic reticulum (ER). Proembryonic cell masses (proembryoids) formed from the scutellar ridge by 10 DAC. Proembryoid cells had abundant Golgi bodies and ER while the amounts of lipids and starch varied. Somatic embryos developed from the proembryonic masses 13 DAC and by 21 DAC had all the parts of mature zygotic embryos. Although shoot and root primordia of somatic embryos were always less differentiated than those of zygotic embryos, scutellar cells of somatic and zygotic embryos had similar amounts of lipids, vacuoles, and starch. Somatic scutellar epidermal cells were more vacuolated than their zygotic counterparts. In contrast, somatic scutellar nodal cells were smaller and not as vacuolated as in zygotic embryos. Somatic embryogenesis was characterized by three phases of cell development: first, scutellar cell dedifferentiation with a reduction in lipids and cell and vacuole size; second, proembryoid formation with high levels of ER; and third, the development of somatic embryos that were functionally and morphologically similar to zygotic embryos.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13871.x

出版商:Wiley    

年代:1996

数据来源: WILEY

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb15768.x

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

Iridescent blue leaf coloration in four Malaysian rain forest understory plants,Diplazium tomentosumBl. (Athyriaceae),Lindsaea lucidaBl. (Lindsaeaceae),Begonia pavoninaRidl. (Begoniaceae), andPhyllagathis rotundifoliaBl. (Melastomataceae) is caused by a physical effect, constructive interference of reflected blue light. The ultrastructural basis for this inD. tomentosumandL. lucidais multiple layers of cellulose microfibrils in the uppermost cell walls of the adaxial epidermis. The helicoidal arrangement of these fibrils is analogous to that which produces a similar color in arthropods. InB. pavoninaandP. rotundifoliathe blue‐green coloration is caused by parallel lamellae in specialized plastids adjacent to the abaxial wall of the adaxial epidermis. The selective advantage of this color production, if any, is unknown.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1996.tb13872.x

出版商:Wiley    

年代:1996

数据来源: WILEY