- A-Z
- Endocytobiosis and ...
- Volume 29
- Phloem’s role in pl...
- Autor(in)
- Seitenbereich
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007-012
- Schlagwort(e)
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calcium, defence, pathogens, phloem, phytohormones, sieve element, sieve-element occlusion, signalling
- Zusammenfsg.
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Systemic signalling via the phloem is essential for plant development and adaption to environmental changes. Perception of pathogens and it’s effectors, triggers signals that reach the phloem to promote sieve element (SE) occlusion. This review focuses on the diverse possible defense mechanisms against microbes associated to the phloem of higher plants. One of the first responses to biotic changes in the environment is the gating of Ca2+-permeable channels to trigger intracellular cascades. Ca2+ can act as a key molecule for the generation and amplification of numerous long-distance signals. Diverse long-distance signals, electrical and chemical, are suggested to play a role in plant defence. Electropotential waves propagate along the vascular pathway induce Ca2+ influx into SE elements with the consequence of SE occlusion. It is presumptive that some chemical signalling substances are produced prior SE occlusion and spread throughout the plant body. The effect of the SE occlusion is to form a physical barrier to restrict pathogens and to accumulate other signal molecules- reversibility ensures a systemic spread of signals.