Endogenous ABA, free and conjugated ACC concentrations, ethylene-forming capacity (EFC), and presence of ACC oxidase (ACO) and ACC synthase (ACS) proteins were monitored during the preharvest maturation period of `Granny Smith' apple fruit (Malus sylvestris L. Mill. var. domestica (Borkh.) Mansf. `Granny Smith'). Total proteins from peel and pulp tissues were also extracted at different maturity stages and separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis, providing evidence of differential protein accumulation during fruit development. Endogenous ABA concentration in the peel tissue was higher than in pulp, the highest level occurring ≈2 months before commercial harvest. In the pulp tissue, concomitant increases in ACC and ABA concentrations were observed, preceded by a peak in EFC. However, no ACO or ripening-related ACS proteins were detectable throughout the period considered, suggesting that very low levels of both enzymes are present during the preclimacteric stage of `Granny Smith' apples. A hypothesis on the possible interaction between ABA and ethylene during maturation of `Granny Smith' apples is proposed. Chemical names used: abscisic acid (ABA); 1-aminocyclopropane-1-carboxylic acid (ACC).
Ahmed Mahhou and Frank G. Dennis Jr.
Siberian C peach (Prunus persica L.) seeds were stratified at 5 and 20C. DWs and soluble protein content remained constant regardless of stratification temperature and duration. Seed extracts subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a decrease in the intensity of nine polypeptides in the cotyledons of seeds held at 5C during weeks 5 through 8, coinciding with an increase in germination capacity. These changes were confined to cotyledons held at 5C, and were observed only when the seeds were able to germinate. The effects of stratification and the imbibition degree on changes in the protein content of seeds of two additional peach biotypes (`Farouki' and `Maloussi') were also evaluated. Germination of fully imbibed seeds at 20C increased steadily as stratification time at 5C increased. Partially imbibed seeds (25 % or 50% of full imbibition) did not germinate regardless of stratification time. However, when these seeds were soaked in water after stratification, their germination paralleled that of fully imbibed seeds. Thus, dormancy was broken, even though the seeds could not germinate. Changes in protein profiles in fully imbibed seeds confirmed those previously reported for Siberian C seeds. Similar changes occurred in cotyledons of partially imbibed seeds during stratification at 5C, but at a slower rate. Those changes were, however, delayed by partial imbibition, whereas germination capacity (ability to germinate when fully imbibed) was not. Changes in cotyledon protein profiles were not affected by removing the embryonic axis before stratification, a result indicating that such changes are not controlled by the axis. Gibberellic acid (GA3 induced 35 % to 40% germination of nonchilled seeds. It hastened the loss of protein band intensity in `Farouki' but not in `Maloussi'. However, GA3-treated seeds germinated before any visible changes occurred in protein profiles. We conclude that the effects of chilling on breaking dormancy are independent of its effects on the protein changes observed in this study.
Ellen T. Paparozzi, Joshua R. Widhalm, and M. Elizabeth Conley
Common swedish ivy plants when exposed to nitrogen (N) stress display typical nitrogen deficiency symptoms such as reddening of stems and petioles and yellowing of leaves. When N levels are restored, leaves of swedish ivy plants will re-green without leaf loss. An experiment was conducted to determine how proteins change when leaves were re-greened after N deficiency. Cuttings of Plectranthus australis were rooted under mist and allowed to yellow. Plants were then potted up and fertilized with one of two treatments: complete nutrients with N at 150 ppm or complete nutrients with 0.8 ppm N. The experimental design was a randomized complete-block design with six blocks. Each block had the two N treatments and six plants per treatment. After 3–4 weeks, all plants in the 150-ppm N treatment had re-greened and leaf samples for protein analysis were taken. Plants in four of the six blocks were then switched to the other treatment. After leaves had re-greened once again, leaf samples were taken and the experiment was terminated. Two-dimensional polyacrylamide gel electrophoresis was used to compare the treatments. No obvious differences in protein absence or presence were noted. However, Rubisco appeared to be differentially expressed between the two treatments. 2-D gel analysis with subsequent Western blots showed that for most of the leaf samples, the large subunit of Rubisco (56kD) was quantitatively about 1.3 times more concentrated in the N-deficient plants and possibly modified. The small subunit (12kD) was not reliably detectable. Additional protein results for repeated leaf re-greening and the role Rubsico may play in leaf re-greening will be discussed.
Hisayo Yamane, Ryutaro Tao, Akira Sugiura, Nathanael R. Hauck, and Amy F. Iezzoni
This report demonstrates the presence of S-ribonucleases (S-RNases), which are associated with gametophytic self-incompatibility (SI) in Prunus L., in styles of self-incompatible and self-compatible (SC) selections of tetraploid sour cherry (Prunus cerasus L.). Based on self-pollen tube growth in the styles of 13 sour cherry selections, seven selections were SC, while six selections were SI. In the SI selections, the swelling of pollen tube tips, which is typical of SI pollen tube growth in gametophytic SI, was observed. Stylar extracts of these selections were evaluated by two-dimensional polyacrylamide gel electrophoresis. Glycoproteins which had molecular weights and isoelectric points similar to those of S-RNases in other Prunus sp. were detected in all selections tested. These proteins had immunological characteristics and N-terminal amino acid sequences consistent with the S-RNases in other Prunus sp. Two cDNAs encoding glycoproteins from `Erdi Botermo' were cloned. One of them had the same nucleotide sequence as that of S4-RNase of sweet cherry (Prunus avium L.), while the amino acid sequence from the other cDNA encoded a novel S-RNase (named Sa-RNase in this study). This novel RNase contained two active sites of T2/S type RNases and five regions conserved among other Prunus S-RNases. Genomic DNA blot analysis using cDNAs encoding S-RNases of sweet cherry as probes indicated that three or four S-RNase alleles are present in the genome of each selection regardless of SI. All of the selections tested seemed to have at least one S-allele that is also found in sweet cherry. Genetic control of SI/SC in tetraploid sour cherry is discussed based on the results obtained from restriction fragment length polymorphism analysis.
Joohee Lee and Yeh-Jin Ahn
. Protein extraction from carrot tissue, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblot analysis using a polyclonal antibody raised against DcHsp17.7 were performed as previously described ( Ahn et al., 2004 ). Briefly
Priscila L. Gratão, Carolina C. Monteiro, Lázaro E.P. Peres, and Ricardo Antunes Azevedo
polyacrylamide gel electrophoresis (PAGE) were carried out as described by Gomes-Junior et al. (2007) . Electrophoresis buffers and gels were prepared as described by Vitória et al. (2001) except that sodium dodecyl sulphate was excluded. The experimental
Hanseul Park, Eunhye Ko, and Yeh-Jin Ahn
, 1976 ), and resolved by performing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE, 17%) followed by immunoblot analysis using a polyclonal antibody raised against DcHsp17.7, as previously described ( Ahn et al., 2004 ). Levels of a
Cunquan Yuan, Zhiyi Qu, Huitang Pan, Tangren Cheng, Jia Wang, and Qixiang Zhang
silver staining method. The polymorphism of the primers was further analyzed by nondenaturing polyacrylamide gel electrophoresis. The primers that met the requirements were further analyzed in the offspring of the hybrid progeny. Screening of SSR markers
Antar Nasr El-Banna, Mohammed Elsayed El-Mahrouk, Mohammed Eraky El-Denary, Yaser Hassan Dewir, and Yougasphree Naidoo
the Genetics Department, Faculty of Agriculture, during 2014–15. Table 1. List of accessions scientific names, collection site, and country of origin. Protein extraction and electrophoresis. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) was carried
Xiaobai Li, Weirui Li, Chenlu Di, Ming Xie, Liang Jin, Cheng Huang, and Dianxing Wu
development. Polymerase chain reaction (PCR) primers were synthesized by Life Technologies (ABI and Invitrogen, Shanghai, China). PCR experiments were conducted, and the products were separated using polyacrylamide gel electrophoresis gel ( Li et al., 2007