Herbivore attack elicits costly defenses that are known to decrease plant fitness by using resources that are normally slated for growth and reproduction. Additionally, plants have evolved mechanisms for tolerating attack, which are not understood on a molecular level. Using 11C-photosynthate labeling as well as sugar and enzyme measurements, we found rapid changes in sink-source relations in the annual Nicotiana attenuata after simulated herbivore attacks, which increased the allocation of sugars to roots.
View Article and Find Full Text PDFWe examined the consistency of the native diploid Nicotiana attenuata (Na)'s herbivore-induced transcriptional changes in the two allotetraploid natives, Nicotiana clevelandii (Nc) and Nicotiana quadrivalvis (Nq), which are thought to be derived from hybridizations with an ancestral Na. An analysis of nuclear-encoded chloroplast-expressed Gln synthetase gene (ncpGS) sequences found strong similarity between Nc and Na and between N. trigonophylla and the two allopolyploids.
View Article and Find Full Text PDFWe investigated the impact of leaf vascular connections on systemically transmitted herbivore-induced gene expression in Nicotiana attenuata. Although systemic signaling is clearly associated with the plant vascular system, few studies consider vascular architecture when measuring systemically induced defenses. N.
View Article and Find Full Text PDFCurr Opin Plant Biol
August 2001
The singer-song-writer Paul Simon sang about the '50 ways to leave your lover'; plants have at least as many ways of coping with their insect herbivores. Recent research has elucidated the mechanisms of direct and indirect plant defenses, and has provided the first proof of a protective function for indirect defenses in nature. Insect attack elicits a large transcriptional reorganization that differs from that elicited by mechanical wounding.
View Article and Find Full Text PDFSpecialist herbivores are known to alter their host's wound-induced responses but the beneficiaries of these alterations are unknown. Nicotiana attenuata plants release a burst of ethylene specifically in response to feeding by Manduca sexta larvae, which is known to suppress wound- and methyl jasmonate (MeJA)-inducible nicotine accumulation. The ethylene burst may be a mechanism by which M.
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