increase the postharvest shelf life of ethylene-sensitive fruits, cut flowers, and potted plants. Most evaluations of ethylene sensitivity have been performed on mature plants or on detached organs (i.e., fruits or cut flowers) ( Archambault et al., 2006
Nichole F. Edelman and Michelle L. Jones
Andrew J. Macnish, Ria T. Leonard, Ana Maria Borda, and Terril A. Nell
et al., 2001 ) and transport-related stress (e.g., water deficit) can stimulate elevated rates of ethylene synthesis by plant tissues ( Muller et al., 2000 ), quantification of the ethylene sensitivity of different rose cultivars could assist future
David G. Clark, Christopher Dervinis, James E. Barrett, and Terril A. Nell
Florida Agricultural Experiment Station journal series R-07081. Use of a seedling hypocotyl elongation assay as a genetic screen for ethylene sensitivity of seedling geranium cultivars. The cost of publishing this paper was defrayed in part
Nichole F. Edelman, Bethany A. Kaufman, and Michelle L. Jones
, epinasty, senescence, and fruit ripening. Plant responses to ethylene depend on the concentration and exposure time (i.e., dosage) as well as the plant’s sensitivity to ethylene. Ethylene sensitivity varies by species, ranging from nonresponsive to highly
Masayasu Nagata, Natsu Tanikawa, and Takashi Onozaki
The plant hormone ethylene plays an important role in the senescence process of carnation flowers. Recently, various genes that concern ethylene responses have been cloned from many sources of plants. Our main aim is to compare the sequences of ethylene receptor genes among carnations with different ethylene sensitivities. Four carnations, `White Sim' (ethylene sensitive control), `Chinera' (lower ethylene sensitivity), 64-13 and 64-54 were used. The carnations temporarily named as 64-13 and 64-54 are our breeding lines with less ethylene sensitivity, thus better flower retention. Total RNA was extracted using SDS-phenol method. Putative ethylene receptor genes were cloned by RT-PCR using degenerate primers that correspond to the highly conserved regions of ETR1 and ERS genes. Two kinds of DNA fragments, ≈1 kb in the length encoding putative ethylene receptor genes were cloned from all samples. An ERS-type gene was cloned that is identical to the gene, known as DC-ERS2 (Accession No. AF034770). Another was ETR1-type gene, which has not been reported in carnations yet. That was 91% identical to the ETR1 gene from melon or apple at the translated amino acid level. The deduced amino acid sequences of ERS-type genes among four samples were almost the same. However there were five mutations in `Chinera', one mutation in 64-13 and two mutations in 64-54, compared to `White Sim' at the translated amino acid level. As they located rather conserved regions of the gene, it is expected to affect the less ethylene sensitivity of the carnations.
Dwight R. Tingley and Timothy A. Prince
A survey of 16 cut evergreen species found six clustered groupings of species based on ethylene production at 2 and 21C. Ethylene production (in nanoliters per kilogram of fresh weight per hour) at 21C ranged from 26 for Juniperus virginiana to 2800 for Sequoia sempervirens. Exposure to 0.1 or 1.0 ppm ethylene for 72 hours at 2C resulted in minor effects on two species, while significantly delaying senescence of Sequoia sempervirens. Silver thiosulfate (STS) pretreatment decreased or increased longevity of six species, but all effects were minor. Longevity of cut evergreens when held in preservative solution ranged from 14 days for Pinus sylvestris to 56 days for Chamaecyparis lawsoniana. Senescence symptoms observed were needle abscission, desiccation, and/or chlorosis.
Meng-Jen Wu, Lorenzo Zacarias, Mikal E. Saltveit, and Michael S. Reid
Continuous treatment with 8% ethanol doubled the vase life of `White Sim' carnation (Dianthus caryophyllus L.) flowers. Other alcohols, other concentrations of ethanol, or pulse treatments with up to 8% ethanol had little or no effect. Butanol and longer-chain alcohols shortened vase life and caused the flower stem to fold. During their eventual senescence, the petals of ethanol-treated flowers did not inroll; instead, individual petals dried slowly from their tips. Very little ethylene was produced by ethanol-treated flowers, and the normal increase in ACC content and EFE activity was also suppressed. Ethanol treatment also decreased the flowers' sensitivity to exogenous ethylene.
Erika K. Gubrium, Donna J. Clevenger, David G. Clark, James E. Barrett, and Terril A. Nell
A series of experiments on ethylene-insensitive (EI) petunia plants (Petunia ×hybrida Hort. Vilm.-Andr.) generated in two genetic backgrounds were conducted to determine the involvement of ethylene in horticultural performance. Experiments examined various aspects of horticultural performance: days to flower, flower senescence after pollination and without pollination, fruit set and ripening, and adventitious root formation on vegetative stem cuttings. The development of EI plants was altered in several ways. Time from seed sowing to first flower anthesis was decreased by a week for EI plants grown at 26/21 °C. Flower senescence in nonpollinated and self-pollinated flowers was delayed in all EI plants compared to wild-type plants. Fruit set percentage on EI plants was slightly lower than on wild-type plants and fruit ripening on EI plants was delayed by up to 7 days. EI plants produced fewer commercially acceptable rooted cuttings than wild-type plants. There was a basic difference in the horticultural performance of the two EI lines examined due to a difference in the genetic backgrounds used to generate the lines. EI plants displayed better horticultural performance when grown with day/night temperatures of 26/21 °C than 30/24 °C. These results suggest that tissue-specific ethylene insensitivity as well as careful consideration of the genetic background used in transformation procedures and growth conditions of etr1-1 plants will be required to produce commercially viable transgenic floriculture crops. EI petunias provide an ideal model system for studying the role of ethylene in regulating various aspects of plant reproduction.
Fritz K. Bangerth, Jun Song, and Josef Streif
volatiles and again this was coupled with lower respiration and depressed FA concentrations compared with later harvested fruit ( Song and Bangerth, 2003 ). This effect of fruit ripening on volatile production seems to be related to ethylene sensitivity
Andrew J. Macnish, Ria T. Leonard, and Terril A. Nell
used to distribute and store foliage plants ( Hoyer, 1995 ; Skog et al., 2001 ). Although ethylene sensitivity varies significantly among potted flowering genotypes ( Muller et al., 1998 ; Serek and Reid, 2000 ; Woltering, 1987 ), the response of