Impact of warming and drought on carbon balance related to wood formation in black spruce
Wood formation in trees represents a carbon sink that can be modified in the case of stress. The way carbon metabolism constrains growth during stress periods (high temperature and water deficit) is now under debate. In this study, the amounts of non-structural carbohydrates for xylogenesis in black spruce saplings were assessed under high temperature and drought in order to determine the role of sugar mobilization for osmotic purposes and its consequences for secondary growth. Plant water status during wood formation can influence the materials available for growth in the cambium and xylem.
Relative growth rate variation of evergreen and deciduous savanna tree species is driven by different traits
Plant relative growth rate depends on biomass allocation to leaves (leaf mass fraction, efficient construction of leaf surface area (specific leaf area) and biomass growth per unit leaf area (net assimilation rate). This paper shows that trade-offs between investment in carbohydrate reserves and growth occur only among deciduous species, leading to differences in relative contribution made by the underlying components of relative growth rate between the leaf habit groups. The results suggest that differences in drivers of relative growth rate occur among savanna species because these have different selected strategies for coping with fire disturbance in savannas.
DEF- and GLO-like proteins may have lost most of their interaction partners during angiosperm evolution
DEFICIENS (DEF)- and GLOBOSA (GLO)-like proteins constitute two groups of floral homeotic transcription factors that were already present in the most recent common ancestor of angiosperms. Together they specify the identity of petals and stamens in flowering plants. This paper strengthens the hypothesis that a reduction in the number of interaction partners of DEF- and GLO-like proteins, with DEF–GLO heterodimers remaining the only DNA-binding dimers in core eudicots, contributing to developmental robustness, canalization of flower development and the diversification of angiosperms.