INEY. 1984. A scanning clcctron microscopc study of thc dcvclopnmcnt and surfacc fcaturcs of floral organs of tomato (Lyc,ol)er:sic,orr esc.rrl~r~t~rrr~). Can. J . Bot. 62: 2403-24 13. The initiation and dcvclopnmcnt and thc surfilcc fcaturcs of floral organs of tomato (Lj,c~ol~envic~o~~ e.sc~lrle~rtrr~rr Mill.) wcrc cxanmincd using scanning clcctron microscopy. Aftcr tlmc transformation of thc vcgctativc apcx into thc floral apcx. thc tlorr~l organs appcarcd in thc following scqucncc: scpals. pctals. stamcns. rund carpcls. 'rhc pattern of initiation was helical for the scpals and simultancous for pctals. stanicns, and carpcls. Thcrc was a progrcssivc incrcasc in thc diamctcr of thc apcx associated with thc initiation of cach whorl of organs. Following initiation. tlmc scpal and pctal prinmordia fuscd at thc bas21 rcgion by "zonal growth," but thc cohcsion of anthcrs to form a staminal tube occurrcd latcr in dcvclopmcnt and was achicvcd by thc interlocking of cpidcrmal hairs produccd on the Intcrnl and adaxial surfnccs of anthcrs. Carpcl prinmordia wcrc produccd at thc circumfcrcncc of thc rcnmaining mcristcm and wcrc fused laterally carly in dcvclopmcnt. Epitlcrnmal hairs of diffcrcnt typcs and frcqucncics wcrc obscrvcd on thc adaxial ant1 abaxial surfaccs of scpals ant1 pctals and on thc adaxial and lateral surfaccs of thc anthcrs. In thc gynoccium. hairs wcrc prcscnt only o n thc lowcr half of thc stylc and wcrc abscnt on thc ovary. Stomata wcrc obscrvcd on tlic scpals. pctals, and stylc. but not on thc anthcrs or ovary. Raised stomata wcrc prcscnt only on young dcvcloping scpals ant1 tlmc stylc and wcrc abscnt on maturc organs. Cuticular thickenings wcrc also obscrvcd on thc abaxial surfaccs of scpals, pctols. and stamcns. but not o n thc gynoccium.--

Comparative studies on the ultrastructure and protein composition of the embryo and endosperm of date palm (Phoenix dactylifera L.) were conducted. Cells of the embryo cotyledon and endosperm function in reserve storage and contained cell walls, nuclei, and cytoplasm rich in lipid and protein bodies. Morphometric analysis from light and electron micrographs showed that the cell walls of the endosperm occupied 65% of the total cell volume, but only 6% in the embryo. The protein bodies of the endosperm accounted for 11%, whereas those of the embryo occupied more than half of the total cell volume. The volume of organelles and organelle‐free cytoplasm in the endosperm was negligible, suggesting that most of the extractable endosperm proteins are localized in the protein bodies. Extractable proteins in the embryo may come from cytoplasm, protein bodies, and other organelles. The endosperm contains relatively lower amounts of proteins than does the embryo. Proteins extracted from both tissues were compared using SDS‐polyacrylamide gel electrophoresis, tube gel isoelectric focusing, and two‐dimensional electrophoresis. Proteins of both the tissues were heterogeneous in molecular mass and charge. The majority of the proteins were similar in molecular mass and charge in the two tissues, suggesting that most of the storage proteins are probably the same. However, there were also several embryo‐ and endosperm‐specific proteins apparent in both the first‐ and second‐dimension gels. The endosperm‐specific proteins may play an important role in germination and seedling development.

No abstract

α-Galactosidases (EC 3.2.1.22) from resting and germinated date (Phoenix dactylifera L.) seeds were compared and localized using immunocytochemical methods. The enzyme was present in both the endosperm and embryo of resting seeds, in the endosperm undergoing digestion where the greatest specific activity was present, and in the haustorium of seedlings. The enzyme had a molecular mass of 140000 as determined by gel filtration and a pH optimum of 4.5. At least seven forms of the enzyme with isoelectric points ranging from 3.85 to 5.2 were detected in the haustorium whereas only four of these forms were present in the endosperm. The relative activity levels of the various forms also differed between the two tissues. On Western blots all enzyme forms were recognized by antibodies raised against mung-bean (Vigna radiata) α-galactosidase. Using immunogold techniques, label was shown to be present in the protein bodies of the resting embryo cells but to decrease in this organelle as the reserve protein was mobilized and to appear diffusely in the cytoplasm in subsequent stages. In resting endosperm cells, label occurred in the protein bodies and in a thin region of inner wall. In endosperm undergoing digestion, where different stages of protoplast and wall breakdown occurred, immunogold staining was localized in the flocculent contents of vacuoles which resulted from storageprotein breakdown, then dense staining occurred in the inner wall of cell cavities formed by the complete dissolution of the cytoplasm, and finally, staining was uniformly diffuse throughout the remaining endosperm wall adjacent to the haustorium surface. These observations indicate that the α-galactosidase present in cell walls of the date palm endosperm during mannan mobilization is not secreted by the haustorium but instead is probably a pregermination product stored mainly in the protein bodies of resting endosperm and is released to the wall following loss of membrane integrity.

To characterize further the events involved in fertilization and early embryonic development in the mare, effect of the estrous cycle on oviductal fluid proteins was investigated. Five mares had indwelling cannulas placed in their oviducts so that fluid could be collected throughout the estrous cycle. Daily fluid volumes were recorded and mares were monitored for signs of standing estrus. Oviductal fluid samples were pooled across mares according to stage of cycle (either estrus or nonestrus) for further analysis. Two-dimensional polyacrylamide gel electrophoresis (PAGE) was used to determine proteins present in estrus-associated and nonestrus-associated equine oviductal fluid as compared to blood serum from the same mares. Oviductal fluid volumes increased significantly during estrus to an average of 3.94 ml/24 hr from 1.44 ml/24 hr during nonestrus. Total oviductal protein increased significantly from 24.6 mg/24 hr during nonestrus to 53.9 mg/24 hr during estrus. One-dimensional PAGE demonstrated that the proteins in equine oviductal fluid were present throughout the cycle and also common to equine serum. Reducing conditions revealed one band at 106 kDa detected only in nonestrus-associated oviductal fluid, while nonreducing conditions revealed bands at 48 and 25 kDa that were present in oviductal fluid in general. Two-dimensional PAGE demonstrated three 50 kDa proteins that were detected only in estrus-associated oviductal fluid and several 24 kDa proteins detected only in nonestrus-associated oviductal fluid. Those proteins found only in estrus-associated oviductal fluid may be vital to the fertilization process, while those found only in nonestrus-associated oviductal fluid may be vital to early embryonic development.