Pii: s1360-1385(02)02275-6

News & Comment
TRENDS in Plant Science Vol.7 No.5 May 2002 Lipopolysaccharide, a potential inducer of plant defense response
plant–bacteria interactions. Pre-treatment acidic β-1, 3-glucanase using cDNA probes from tomato. They showed that inoculation them directly. Lipopolysaccharide (LPS) is leaves. They concluded that LPS activates but acidic β-1, 3-glucanase was not induced.
This implies that the effects of LPS on the and on HR suppression, are distinct.
LPS from both X. campestris pv. campestris accelerated synthesis of two antibacterial a wider role for LPS in plant–bacterial interactions, beyond its limited activity as a direct inducer of plant defense.
enzyme that catalyzes the synthesis of FT and CT), but not PAL transcripts (an enzyme ‘…LPS appears to have two effects that
that catalyzes the CoA derivatives via the could impinge on the timing of FT and
CT synthesis…’
results, they concluded that LPS appears to have two effects that could impinge on the timing of FT and CT synthesis: (1) directly (TyDC) and (2) increasing the potency of the The main challenge faced by biologists to dissect these diverse effects and to exploit working as free compounds, FT and CT will plants to resist bacterial diseases.
growth of Xanthomonas axonopodis pv.
1 Newman, M-A. et al. (2002) Prior exposure to lipopolysaccharide potentiates expression of defenses in response to bacteria. Plant J. 29, tyramine (CT) and feruloyl-tyramine (FT), proteins PR6, basic β-1, 3-glucanase and Tailor-made toxin target
specifically processed to yield a susceptible alternata has a wide host range. However, the sensitivity or resistance of different citrus certain pathotypes are selectively virulent cultivars to the ACR-producing fungus, but and cause brown spots on leaves and fruits ‘…ACRS might function as part of a
rather a post-transcriptional modification of of specific species or cultivars of Citrus, transmembrane pore complex – a common
the ACRS RNA. The ACRS gene has identical target for fungal and bacterial toxins.’
sequences in all Citrus species analyzed, but different transcript size in the susceptible specific toxins. The so-called ACR toxin of the rough lemon pathotype (RLP) causes citrus elegant functional assay in ACR-resistant lemon. Physiological and ultrastructural data had previously suggested that mitochondria lemon and seems to be present as a partially were the site of action of the ACR toxin.
identification of a sequence that conferred sodium dodecyl sulfate-insoluble oligomer Kouhei Ohtani and colleagues [1] have now sensitivity to the toxin. Surprisingly, the provided a surprising explanation for the responsible gene is located in the intron selectivity: the RNA of a mitochondrial gene complex – a common target for fungal and surprisingly, it is not the mere presence or http://plants.trends.com 1360-1385/02/$ – see front matter 2002 Elsevier Science Ltd. All rights reserved. News & Comment
TRENDS in Plant Science Vol.7 No.5 May 2002 1 Ohtani, K. et al. (2002) Sensitivity to Alternaria been previously identified as a basis for uninfected tissues, as well as to find out alternata toxin in citrus because of alteredmitochondrial RNA processing. Proc. Natl.
different mitochondrial protein equipment, opening or closing a gate to an enemy.
Roman Ulm
of action of ACR. Further, it will be of Ortrun Mittelsten Scheid
interest to describe the precise function Trials of pine DNA
abscisic acid. Previously, scientists knew that abscisic acid becomes activated in plants Tsukuba Botanical Gardens (Japan), and in under drought stress. The researchers found subtropical forests, they have evidence that that abscisic acid works by encouraging cells tropical plants produce a large amount of around the stomata to produce nitric oxide.
methyl chloride. Specifically, particular fern This increase in nitric oxide signals the stomata to close, which allows the plant to retain water and turgor. It is hoped that this insight into the role of NO in stomatal biology Have pathogen, will
recombine
plants do not play the victim, but instead DNA evidence from a Norwegian pine forest New spin on crop protection
unleash a variety of responses to ward off the offending bug. Unexpectedly, plants respond help determine who is the real criminal. to pathogen attack by recombining their DNA In 1999, three people were shot dead at a (Cornell University, New York, NY, USA) are in vegetative tissues [Nat. Genet. (2002) 30, farmhouse surrounded by the pine trees in examining ethylene vinyl acetate (EVA) as 311–314]. Jan M. Lucht and colleagues used Lillestroem, just north of Oslo, Norway.
an alternative to pesticides to control plant a clever transgenic system in Arabidopsis One of the convicted killers, Kristin Kirkemo multidimensional fiber barrier’ (which looks blue-staining cells. When the researchers like ‘cotton candy’) to crop species such as sprayed plants with fungus, the amount of fingerprinted the needles and found that the onions and broccoli. EVA provides a physical recombination significantly increased. The needles did not originate from most of the barrier that prevents insect pests getting to same result was also found when the group sprayed on salicylic acid-like chemicals that 42 possible trees). Leif Sundheim, research ravage such crop plants. Although only at responses. Lastly, the experimenters used a Institute told reporters ‘Courts use DNA from mutant deficient in plant defense and found human hair, blood or sperm quite extensively.
environmentally friendlier alternative to that it showed decreased recombination.
We’re using the same techniques with plants.’ insecticides. [http://www.news.cornell.edu/ The recombination might be a general way The police suspect that the killers put socks over their shoes to hide footprints. [Reuters (2002) Toronto Star 13 March, p. NE24] TS Tropical ozone control?
Oldest germinating seed
VIAGRA helps plants’ turgor
VIAGRA (Pfizer, New York, NY, USA), the germinated lotus seeds nearly 500 years old name-brand drug for male sexual turgor, has [Am. J. Bot. (2002) 89, 236–247]. The team turgor as well. VIAGRA gives the body an also naturally from plants. However, there extra dose of nitric oxide, which dilates blood Chinese village of Xipaozi. All four seeds vessels. Researchers Carlos Garcia-Mata and that they tested for viability germinated Lorenzo Lamattina [Plant Physiol. (2002) 128, Yoko Yokouchi and colleagues report that a and were between 200 and 500 years old.
790–792] and Steven Neill and colleagues [Plant Physiol. (2002) 128, 13–16] have made comes from tropical plants [Nature (2002) abnormalities in their leaves, stalks and a new connection between nitric oxide and 416, 163–165]. From their measurements in http://plants.trends.com 1360-1385/02/$ – see front matter 2002 Elsevier Science Ltd. All rights reserved.

Source: http://www.unige.ch/sciences/biologie/bioveg/ulm/publications/Ulm_TIPS_2002_1.pdf