Contrasting alien effects on native diversity along biotic and abiotic gradients in an arid protected area.

Alien impact on native diversity could be a function of both the relatedness of alien species to native community and resources availability. Here, we investigated whether alien plants expand or decrease the functional and phylogenetic space of native plant communities, and how this is affected by alien relatedness to natives and by resources availability. We used a trait-environment dataset of 33 alien and 130 native plants in 83 pairs of invaded and non-invaded plots, covering a gradient of soil resources (organic matter-nitrogen) in Saint-Katherine-Protectorate, Egypt.

Maturation of Atriplex halimus L. leaves involves changes in the molecular regulation of stomatal conductance under high evaporative demand and high but not low soil water content.

Under high water availability, the maximum gas exchange was observed at noon in the expanding and expanded leaves. The expanded leaves showed lower gas exchange capacity due to the regulation of stomatal-movement genes. Under well-watered condition, stomatal conductance (g) and photosynthetic rate (A) of expanding and expanded leaves of Atriplex halimus peaked at noon despite the midday decline in the leaf relative water content, suggesting deviation from typical isohydric behaviour.

Proline induces the expression of salt-stress-responsive proteins and may improve the adaptation of Pancratium maritimum L. to salt-stress.

Proline is an important component of salt-stress responses of plants. In this study the role of proline as part of salt-stress signalling in the desert plant Pancratium maritimum L. was examined.