共查询到6条相似文献,搜索用时 0 毫秒
1.
Zhihua Wang Jianhua Song Yong Zhang Baoyu Yang Shiyun Chen 《Biotechnology letters》2009,31(4):585-589
Expression of baculovirus anti-apoptotic p35 gene in plants on biotic stress responses has been well studied but its function on abiotic stress has not been documented.
In the present study, the p35 gene from Autographa californica multiple nucleopolyhedrovirus (AcMNPV) was expressed in tobacco. A detached leaf assay was used to test tolerance of p35 transgenic plants to various abiotic stress responses. Expression of p35 gene in tobacco gave tolerance to treatment with methanol and H2O2 and also delayed leaf senescence under starvation in the dark. Germination of T0 seeds on NaCl-containing medium also demonstrated to increase salt tolerance. 相似文献
2.
Perturbing CAX1, an Arabidopsis vacuolar H+/Ca2+ antiporter, and the related vacuolar transporter CAX3, has been previously shown to cause severe growth defects; however,
the specific function of CAX3 has remained elusive. Here, we describe plant phenotypes that are shared among cax1 and cax3 including an increased sensitivity to both abscisic acid (ABA) and sugar during germination, and an increased tolerance to
ethylene during early seedling development. We have also identified phenotypes unique to cax3, namely salt, lithium and low pH sensitivity. We used biochemical measurements to ascribe these cax3 sensitivities to a reduction in vacuolar H+/Ca2+ transport during salt stress and decreased plasma membrane H+-ATPase activity. These findings catalog an array of CAX phenotypes and assign a specific role for CAX3 in response to salt
tolerance. 相似文献
3.
4.
Ariadna Peremarti Ludovic Bassie Paul Christou Teresa Capell 《Plant molecular biology》2009,70(3):253-264
Polyamines are known to play important roles in plant stress tolerance but it has been difficult to determine precise functions
for each type of polyamine and their interrelationships. To dissect the roles of putrescine from the higher polyamines spermidine
and spermine, we generated transgenic rice plants constitutively expressing a heterologous S-adenosylmethionine decarboxylase (SAMDC) gene from Datura stramonium so that spermidine and spermine levels could be investigated while maintaining a constant putrescine pool. Whereas transgenic
plants expressing arginine decarboxylase (ADC) produced higher levels of putrescine, spermidine and spermine, and were protected from drought stress, transgenic plants
expressing SAMDC produced normal levels of putrescine and showed drought symptoms typical of wild type plants under stress,
but the transgenic plants showed a much more robust recovery on return to normal conditions (90% full recovery compared to
25% partial recovery for wild type plants). At the molecular level, both wild type and transgenic plants showed transient
reductions in the levels of endogenous ADC1 and SAMDC mRNA, but only wild type plants showed a spike in putrescine levels under stress. In transgenic plants, there was no spike
in putrescine but a smooth increase in spermine levels at the expense of spermidine. These results confirm and extend the
threshold model for polyamine activity in drought stress, and attribute individual roles to putrescine, spermidine and spermine. 相似文献
5.
Nottrott S Schoentaube J Genth H Just I Gerhard R 《Apoptosis : an international journal on programmed cell death》2007,12(8):1443-1453
Clostridium difficile toxin A (TcdA) is one of two homologous glucosyltransferases that mono-glucosylate Rho GTPases. HT29 cells were challenged
with wild-type and mutant TcdA to investigate the mechanism by which apoptosis is induced. The TcdA-induced re-organization
of the actin cytoskeleton led to an increased number of cells within the G2/M phase. Depolymerization of the actin filaments
with subsequent G2/M arrest, however, was not causative for apoptosis, as shown in a comparative study using latrunculin B.
The activation of caspase-3, -8, and -9 strictly depended on the glucosylation of Rho GTPases. Apoptosis measured by flow
cytometry was completely abolished by a pan-caspase inhibitor (z-VAD-fmk). Interestingly, cleavage of procaspase-3 and Bid
was not inhibited by z-VAD-fmk, but was inhibited by the calpain/cathepsin inhibitor ALLM. Cleavage of procaspase-8 was susceptible
to inhibition by z-VAD-fmk and to the caspase-3 inhibitor Ac-DMQD-CHO, indicating a contribution to the activation of caspase-3
in an amplifying manner. Although TcdA induced mitochondrial damage and cytochrome c release, p53 was not activated or up-regulated. A p53-independent apoptotic effect was also checked by treatment of HCT 116
p53−/− cells. In summary, TcdA-induced apoptosis in HT29 cells depends on glucosylation of Rho GTPases leading to activation of
cathepsins and caspase-3. 相似文献
6.
We tested whether maternal effects have led to the adaptive divergence of strains of the natural hybrid Potamogeton anguillanus, whose putative parents show contrastingly divergent ecologies. To examine the correlation between phenotypic characters
and maternal types, we conducted drought experiments and DNA typing using nuclear and chloroplast genes. In the field, we
investigated the distribution of the maternal type along the depth and the inshore-offshore gradient. Hybrids of P. malaianus mothers (M-hybrids) and those of P. perfoliatus mothers (P-hybrids) could not be distinguished morphologically under submerged conditions, but differed in drought tolerance.
M-hybrids and P. malaianus formed more terrestrial shoots and exhibited higher survival than P-hybrids and P. perfoliatus in drought experiments. The distribution survey clarified that M-hybrids were dominant in shallow and inshore areas, whereas
they were almost absent in deeper and offshore areas. These results indicate that the natural hybrid P. anguillanus differs in adaptive values depending on the maternal type. Bidirectional hybridization and heritable maternal effects may
have played important roles in its phenotypic adaptation to local environmental conditions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献