596 research outputs found
Postharvest investigations into chlorophyll fluorescence and low temperature injury in cut roses (Rosa hybrida L.)
No full textThis is one of the first studies on the relationship between pre-harvest
environmental conditions found in the Mediterranean and postharvest characteristics
of cut roses (Rosa hybrida L. ). Effects of storage temperature on vase life parameters
were also studied for roses grown all year round. The postharvest storage of roses at
low temperature is a useful practice, in terms of market flow regulation. However, a
reduction in vase life and loss of flower quality has been recorded after storage due to
Low Temperature Injury (LTI). LTI of roses is difficult to assess by visual
observation. Relative chlorophyll fluorescence (F'IFR, ), which is a non-invasive
technique that provides an index of stress effects on photosystem II (PS II) activity,
was used to investigate LTI in roses. The plant growth regulator abscisic acid (ABA)
can cause physiological responses that protect plants against CI or LTI. The overall
objectives of this study were firstly to evaluate the pre-harvest environmental
conditions affecting vase life and secondly to evaluate novel potential ABA
treatments to protect cut roses against LTI.
Vase life durations and Fv. /Fm ratios measured after low temperature storage
for `First Red' and `Akito' roses were seasonally dependant. Vase lives of roses
grown during winter were significantly (P
_<
0.001) shorter compared to roses grown
during the rest of the year. In autumn and winter experiments F.. IF.. ratios were
generally reduced following storage at 1°C, suggesting LTI of roses. Thus, the fall of
F,. /Fm was due to an interaction of growing season and storage at I. T. However, in
second year experiments, growing temperature and PFD were relatively higher and, as
a result, Fý/Fm did not decline for `Akito' roses after low temperature storage,
indicating a strong influence of environmental conditions. Higher PFD and
temperature glasshouse during the year were positively and significantly correlated
with maintenance of post-storage Fv. /Fm ratios and longer vase life. It is suggested
that shorter vase lives and lower post-storage FV/Fm values after storage at 1°C are
consequences of reduced photosynthesis and smaller carbohydrate pools in winter-
harvested roses. Because of the lack of correlation between Fv. /Fm and post-storage
vase life, it is concluded that the CF parameter F,. /Fm is not a practical index for
assessing LTI in cold-stored roses. Growing roses in autumn and winter months increased flower blueing in red petals of `First Red' roses and prevented flower
opening for both cultivars.
ABA applied as pulse treatment before storage or as vase solution during vase
life generally improved vase life parameters. Pulsing `Akito' roses with 10-1 M ABA
before storage increased vase life and inhibited bent neck incidence. Also, the
presence of ABA in vase solution increased vase life after storage at 1°C, reducing
vase solution usage during vase life. Similarly, the synthetic ABA analogue PBI-365,
as vase solution ingredient, was effective in extending vase life and reducing
transpiration rates in roses after low temperature storage. Increased ABA levels were
detected in leaves and petals using HPLC when roses were treated with exogenous
ABA before storage and during vase life. Thus, it was assumed that ABA or PBI-365
acted on guard cells by causing stomatal closure. Electrolyte leakage and lipid
peroxidation, measured after storage at 1°C, were markedly reduced by application of
ABA. Both pulse ABA treatment and vase solutions containing ABA helped to
recover F,, /Fm during vase life. Moreover, addition of PBI-365 in vase solution
reduced the degree of lipid peroxidation in leaves and petals after storage at 1°C.
These observations indicated a protection role of ABA against LTI for roses, which
has also been observed in other crops.
Further research at the cellular and/or molecular level may help in better
understanding the physiological responses of roses to seasonal variation during the
year and LTI. In addition, work is also required to look at the ABA and PBI-365
mode of action in roses. Additional research using a wide range of ABA
concentrations and assays using exogenous radio-labelled ABA may help to better
understand the nature of ABA efficacy
Did Plant Patents Create the American Rose?
No full textThe Plant Patent Act of 1930 was the first step towards creating property rights for biological innovation: it introduced patent rights for asexually-propagated plants. This paper uses data on plant patents and registrations of new varieties to examine whether the Act encouraged innovation. Nearly half of all plant patents between 1931 and 1970 were for roses. Large commercial nurseries, which began to build mass hybridization programs in the 1940s, accounted for most of these patents, suggesting that the new intellectual property rights may have helped to encourage the development of a commercial rose breeding industry. Data on registrations of newly-created roses, however, yield no evidence of an increase in innovation: less than 20 percent of new roses were patented, European breeders continued to create most new roses, and there was no increase in the number of new varieties per year after 1931.
Therapeutic considerations for APOE and TOMM40 in Alzheimers disease: A tribute to Allen Roses MD
No full textIntroduction: Four years ago this Autumn, pioneering neurologist Prof. Allen. D. Roses passed away. Hence, we have taken time to reflect on his work and legacy in Alzheimer’s disease (AD) research. Prof. Roses rejected the widely accepted amyloid hypothesis, which identifies amyloid beta (Aβ) protein accumulation within the brain as the cause of AD. Instead, he proposed that the epsilon type 4 allele of apolipoprotein (APOE- Ɛ4) and translocase of outer mitochondrial membrane 40 homolog (TOMM40) were preeminent factors in the pathogenesis and progression of AD, particularly in late-onset AD (LOAD). This rejection of the amyloid hypothesis has generated new investigations into APOE and TOMM40 as risk factors for AD. Areas covered: We discuss the contributions of Prof. Roses to AD research, describe how APOE-Ɛ4 and TOMM40 have been posited to trigger neuropathological changes leading to AD, and explore paths to future clinical applications built on the foundations of his research. Expert opinion: The unconventional methodology of targeting APOE and TOMM40 offers great potential for the development of effective preventive and disease-modifying AD interventions. Future preclinical and clinical investigations will greatly benefit from the groundbreaking scientific discoveries of Prof. Roses
The Medical and Economic Roles of Pipeline Pharmacogenetics: Alzheimer's Disease as a Model of Efficacy and HLA-B*5701 as a Model of Safety
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