33 research outputs found
Transcriptomic responses of Solanum dulcamara to natural and simulated herbivory
Plants are attacked by diverse herbivores and respond with manifold defence
responses. To study transcriptional and other early regulation events of these
plant responses, herbivory is often simulated to standardize the temporal and
spatial dynamics that vary tremendously for natural herbivory. Yet, to what
extent such simulations of herbivory are able to elicit the same plant
response as real herbivory remains largely undetermined. We examined the
transcriptional response of a wild model plant to herbivory by lepidopteran
larvae and to a commonly used herbivory simulation by applying the larvae's
oral secretions to standardized wounds. We designed a microarray for Solanum
dulcamara and showed that the transcriptional responses to real and to
simulated herbivory by Spodoptera exigua overlapped moderately by about 40%.
Interestingly, certain responses were mimicked better than others; 60% of the
genes upregulated but not even a quarter of the genes downregulated by
herbivory were similarly affected by application of oral secretions to wounds.
While the regulation of genes involved in signalling, defence and water stress
was mimicked well by the simulated herbivory, most of the genes related to
photosynthesis, carbohydrate- and lipid metabolism were exclusively regulated
by real herbivory. Thus, wounding and application of oral secretions decently
mimics herbivory-induced defence responses but likely not the reallocation of
primary metabolites induced by real herbivory
Redox-engineering enhances maize thermotolerance and grain yield in the field
Contains fulltext :
252904.pdf (Publisher’s version ) (Open Access)08 juli 202
Interactive Responses of Solanum Dulcamara to Drought and Insect Feeding are Herbivore Species-Specific
In nature, plants are frequently subjected to multiple biotic and abiotic stresses, resulting in a convergence of adaptive responses. We hypothesised that hormonal signalling regulating defences to different herbivores may interact with drought responses, causing distinct resistance phenotypes. To test this, we studied the hormonal and transcriptomic responses of Solanum dulcamara subjected to drought and herbivory by the generalist Spodoptera exigua (beet armyworm; BAW) or the specialist Leptinotarsa decemlineata (Colorado potato beetle; CPB). Bioassays showed that the performance of BAW, but not CPB, decreased on plants under drought compared to controls. While drought did not alter BAW-induced hormonal responses, it enhanced the CPB-induced accumulation of jasmonic acid and salicylic acid (SA), and suppressed ethylene (ET) emission. Microarray analyses showed that under drought, BAW herbivory enhanced several herbivore-induced responses, including cell-wall remodelling and the metabolism of carbohydrates, lipids, and secondary metabolites. In contrast, CPB herbivory enhanced several photosynthesis-related and pathogen responses in drought-stressed plants. This may divert resources away from defence production and increase leaf nutritive value. In conclusion, while BAW suffers from the drought-enhanced defences, CPB may benefit from the effects of enhanced SA and reduced ET signalling. This suggests that the fine-tuned interaction between the plant and its specialist herbivore is sustained under drought
Low Salicylic Acid Level Improves Pollen Development Under Long-Term Mild Heat Conditions in Tomato
Exposure to high temperatures leads to failure in pollen development, which may have significant implications for food security with ongoing climate change. We hypothesized that the stress response-associated hormone salicylic acid (SA) affects pollen tolerance to long-term mild heat (LTMH) (≥14 days exposure to day-/nighttime temperature of 30–34/24–28°C, depending on the genotype), either positively, by inducing acclimation, or negatively, by reducing investment in reproductive development. Here, we investigated these hypotheses assessing the pollen thermotolerance of a 35S:nahG tomato line, which has low SA levels. We found that reducing the SA level resulted in increased pollen viability of plants grown in LTMH and further characterized this line by transcriptome, carbohydrate, and hormone analyses. Low expression of JAZ genes in 35S:nahG and LTMH hypersensitivity of low-jasmonic acid (JA) genotypes together suggest that the increased pollen thermotolerance in the low-SA line involves enhanced JA signal in developing anthers in LTMH. These findings have potential application in the development of more thermotolerant crops