Pollinator Proboscis Length Plays a Key Role in Floral Integration of Honeysuckle Flowers (Lonicera spp.).

Pollinator-mediated selection is supposed to influence floral integration. However, the potential pathway through which pollinators drive floral integration needs further investigations. We propose that pollinator proboscis length may play a key role in the evolution of floral integration. We first assessed the divergence of floral traits in 11 Lonicera species. Further, we detected the influence of pollinator proboscis length and eight floral traits on floral integration. We then used phylogenetic structural equation models (PSEMs) to illustrate the pathway through which pollinators drive the divergence of floral integration. Results of PCA indicated that species significantly differed in floral traits. Floral integration increased along with corolla tube length, stigma height, lip length, and the main pollinators' proboscis length. PSEMs revealed a potential pathway by which pollinator proboscis length directly selected on corolla tube length and stigma height, while lip length co-varied with stigma height. Compared to species with short corolla tubes, long-tube flowers may experience more intense pollinator-mediated selection due to more specialized pollination systems and thus reduce variation in the floral traits. Along elongation of corolla tube and stigma height, the covariation of other relevant traits might help to maintain pollination success. The direct and indirect pollinator-mediation selection collectively enhances floral integration.

Chlorogenic acid ameliorates Klebsiella pneumoniae-induced pneumonia in immunosuppressed mice via inhibiting the activation of NLRP3 inflammasomes.

Chlorogenic acid (CGA) possesses a wide variety of bioactive properties, such as antioxidation, anti-inflammation and anti-bacteria. This study was aimed at exploring the effects of CGA of anti-inflammation and anti-bacteria on mouse pneumonia prepared by immunosuppressed mice infected with Klebsiella pneumoniae (K. pneumoniae) in vivo and the cellular inflammasomes through lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced RAW 264.7 murine macrophages in vitro. Mice received CGA treatment (30 and 90 mg kg-1) for 8 consecutive days and on the fourth day immunosuppression in mice was induced by cyclophosphamide (40 mg kg-1) for 5 days before inoculation of K. pneumoniae. Immunosuppressed mice infected with K. pneumoniae developed severe pneumonia, with marked interstitial vascular congestion, widened alveolar intervals, infiltration of monocytes, lymphocytes and macrophages as well as the damage of epithelial architecture, with growing mortality and count forming unit (CFU). CGA treatment significantly decreased the ratio of lung/body weight, reduced the severity of pneumonia induced by K. pneumoniae, decreased the lung injury, inflammatory cell infiltration scores and CD68 protein expression, inhibited the expression of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and elevated the expression of IL-10. Meanwhile, we investigated the mechanism of CGA to counter K. pneumoniae-induced pneumonia and found that CGA remarkably repressed the activation of nucleotide-binding domain like receptor protein 3 (NLRP3) inflammasome. Altogether, our results indicate that the dietary intake of CGA or its rich foods ameliorates K. pneumonia-induced pneumonia by inhibiting the activation of NLRP3 inflammasomes.

Sequential stamen maturation and movement in a protandrous herb: mechanisms increasing pollination efficiency and reducing sexual interference.

Successive stamen movement directly controls pollen presentation schedules through sequential stamen maturation and changes the extent of herkogamy by altering the positions of sexual organs. However, the implications of such movements in terms of pollination are not well understood. Pollen presentation theory predicts that staggered pollen presentation should be favoured when plants are subject to diminishing returns on pollen transfer. Herkogamy on the other hand, has been interpreted as an adaptive trait that reduces sexual interference in hermaphrodite flowers. In this study, we conducted floral manipulations to determine the function of successive stamen movement in pollen transfer. By artificially manipulating the flowers to present two anthers simultaneously in the floral centre, we attempted to investigate whether changes in the anther presentation strategy affect pollen removal, deposition and the efficiency of pollinators. Compared with the natural treatment, the pollen transfer efficiency of halictid bees decreased significantly when the flowers were manipulated to present two anthers simultaneously. Although the presentation of two anthers simultaneously led to a similar pollen removal rate, there was a significant reduction in pollen deposition on neighbouring stigmas. To evaluate the effect of movement herkogamy on pollen export and deposition and seed set, the flowers were manipulated with or without the movement of stamen bending out from the floral centre. Pollen export decreased significantly when the central anther was moved away from the pistil, and pollen deposition and seed set declined significantly when the five spent anthers were retained on the pistil. Our study provides good support for the pollen presentation theory and provides direct experimental evidence that successive stamen movement could increase pollen transfer efficiency by sequential stamen maturation. Moreover, movement herkogamy promotes pollen export, deposition and seed set, and could therefore be regarded as an effective mechanism to reduce interference between male and female functions.