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Corticular photosynthesis drives bark water uptake to refill embolized vessels in dehydrated branches of Salix matsudana
Author(s) -
Liu Junxiang,
Gu Lin,
Yu Yongchang,
Huang Ping,
Wu Zhigang,
Zhang Qian,
Qian Yongqiang,
Wan Xianchong,
Sun Zhenyuan
Publication year - 2019
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13578
Subject(s) - xylem , photosynthesis , chemistry , bark (sound) , water transport , embolism , dehydration , botany , hydraulic conductivity , stomatal conductance , horticulture , biology , water flow , biochemistry , environmental science , soil water , ecology , medicine , environmental engineering , cardiology
It is well known that xylem embolism can be repaired by bark water uptake and that the sugar required for embolism refilling can be provided by corticular photosynthesis. However, the relationship between corticular photosynthesis and embolism repair by bark water uptake is still poorly understood. In this study, the role of corticular photosynthesis in embolism repair was assessed using Salix matsudana branch segments dehydrated to −1.9 MPa ( P 50 , water potential at 50% loss of conductivity). The results indicated that corticular photosynthesis significantly promoted water uptake and nonstructural carbohydrate ( NSC ) accumulation in the bark and xylem during soaking, thereby effectively enhancing the refilling of the embolized vessels and the recovery of hydraulic conductivity. Furthermore, the influence of the extent of dehydration on the embolism refilling enhanced by corticular photosynthesis was investigated. The enhanced refilling effects were much higher in the mildly dehydrated (−1.5 MPa) and moderately dehydrated (−1.9 MPa) branch segments than in the severely dehydrated (−2.2 MPa) branch segments. This study provides evidence that corticular photosynthesis plays a crucial role in xylem embolism repair by bark water uptake for mildly and moderately dehydrated branches.