Potassium‐Dependent Cambial Growth in Poplar

Abstract

To study the involvement of potassium in wood formation, poplar plants ( Populus tremula L. x Populus tremuloides Michx.) were grown over a period of one growing season, under different potassium regimes. Seasonal changes in cambial potassium content, osmotic potential, and cambial activity correlated strongly throughout the season, increasing from spring to summer and decreasing from summer to autumn. Moreover, changing the potassium supply during the growing season affected the seasonal changes of these parameters in a similar way. Low potassium supply markedly reduced cambial activity, the number of expanding cambial cell derivatives, the seasonal rate of radial wood increment, and the vessel frequency. The possible effect of hormones on potassium-dependent cambial growth was investigated and revealed that abscisic acid (ABA) strongly decreased the potassium content within the cambial zone and reduced cambial activity, as well as the number of expanding cambial cell derivatives. In summary, our results indicate a key role for potassium in the regulation of cambial growth and wood formation due to its strong impact on osmoregulation in expanding cambial cells. They also demonstrate involvement of ABA in regulation of potassium-dependent cambial growth.

Linking Biomass Productivity to Genotype-Specific Nutrient Cycling Strategies in Mature Hybrid Poplars Planted Along an Environmental Gradient

“…Each data point is the mean of three replicates the lowest resorption proficiency for growth-limiting nutrients (N and P). Clone D × N-131 was also the least proficient clone at resorbing K (Table 3), a key nutrient for the regulation of cambial growth and wood formation in poplars [69].…”

What Makes the Wood? Exploring the Molecular Mechanisms of Xylem Acclimation in Hardwoods to an Ever-Changing Environment

“…Vessel expansion depends on the activity of potassium (K + ) uptake transporters (e.g., PtrKUP1) and outward rectifying K + channels (e.g., PTORK) [55]. In agreement with a high requirement for K + to regulate turgor pressure, the cambium contains the highest K + concentrations [56]. Furthermore, KUPs show seasonal regulation with high expression levels in wood [57].…”

Understanding calcium functionality by examining growth characteristics and structural aspects in calcium-deficient grapevine

“…1 C), which increases due to adding xylem vessels via secondary growth 43 , contradicts this premise as it did not vary between the Ca 2+ -deficient and Ca 2+ -sufficient vines. This means that secondary growth can also be induced by other processes such as high osmotic pressure in cambial cells 12 and increased cell enlargement and differentiation in the secondary xylem as found in Ca 2+ -deficient Pinus taeda 38 . On the country, Venning 44 found a reduction in cambial activity and secondary xylem in calcium-deficient tomato ( Lycopersicon spp.)…”

“…Progress in this endeavor requires in-depth characterization and fundamental understanding of the symptomatology of organs in different plants at the whole plant and cellular levels by conducting starvation studies under controlled conditions 1 , 9 , 10 . Unlike other nutrients 11 , 12 , the links between Ca 2+ deficiency and its symptomatology in different organs, including the complex interaction among other nutrients in its absence in various crops, are paradoxical, hence the limited understanding of its functionality 5 . This conundrum ensues because tissue requirements for Ca 2+ are genetically controlled, expressing at different extents 7 , 13 .…”