TY - JOUR
T1 - Rapid adjustment of leaf angle explains how the desert moss, Syntrichia caninervis, copes with multiple resource limitations during rehydration
AU - Wu, Nan
AU - Zhang, Yuan Ming
AU - Downing, Alison
AU - Aanderud, Zachary T.
AU - Tao, Ye
AU - Williams, Steven
PY - 2014
Y1 - 2014
N2 - Although the desert moss Syntrichia caninervis Mitt. is extremely desiccation tolerant, it still requires water and photosynthates for growth. The ecological significance of the leaf angle in maintaining a balance between water and light availability is critical to its survival. Active leaf repositioning balances water and light availability following rehydration. S. caninervis can adjust leaf angles from a steep (84-69°) to a stable level at 30° within 7s after rehydration, obtaining maximum net photosynthetic gain at a shoot relative water content of ∼60%. Leaf morphological characters, (leaf hair points, surface papillae and costal anatomy) and ultrastructural changes (chloroplast reordering and loss of lipid reserves as shown by changes in osmiophilic globules) were linked to rapid leaf spreading, water gain and sunlight reflectivity of leaves during rehydration. The high 377.20±91.69 (cm2g-1) surface area to mass ratio was a major factor in facilitating the rapid response to rewetting. Hyaline cells of the leaf base absorbed water, swelled and forced the leaf away from the stem as soon as rehydration commenced. Loss of leaf hair points retards leaf angle adjustment during rehydration.
AB - Although the desert moss Syntrichia caninervis Mitt. is extremely desiccation tolerant, it still requires water and photosynthates for growth. The ecological significance of the leaf angle in maintaining a balance between water and light availability is critical to its survival. Active leaf repositioning balances water and light availability following rehydration. S. caninervis can adjust leaf angles from a steep (84-69°) to a stable level at 30° within 7s after rehydration, obtaining maximum net photosynthetic gain at a shoot relative water content of ∼60%. Leaf morphological characters, (leaf hair points, surface papillae and costal anatomy) and ultrastructural changes (chloroplast reordering and loss of lipid reserves as shown by changes in osmiophilic globules) were linked to rapid leaf spreading, water gain and sunlight reflectivity of leaves during rehydration. The high 377.20±91.69 (cm2g-1) surface area to mass ratio was a major factor in facilitating the rapid response to rewetting. Hyaline cells of the leaf base absorbed water, swelled and forced the leaf away from the stem as soon as rehydration commenced. Loss of leaf hair points retards leaf angle adjustment during rehydration.
KW - desiccation
KW - leaf angle adjustment
KW - leaf hair points (LHPs)
UR - http://www.scopus.com/inward/record.url?scp=84891822008&partnerID=8YFLogxK
U2 - 10.1071/FP13054
DO - 10.1071/FP13054
M3 - Article
C2 - 32480976
AN - SCOPUS:84891822008
SN - 1445-4408
VL - 41
SP - 168
EP - 177
JO - Functional Plant Biology
JF - Functional Plant Biology
IS - 2
ER -