Anatomical variation of mesophyll conductance due to salt stress in Populus cathayana females and males growing under different inorganic nitrogen sources
Anatomical variation of mesophyll conductance due to salt stress in Populus cathayana females and males growing under different inorganic nitrogen sources
复制标题
不同无机氮源下青杨雌雄因盐胁迫引起的叶肉导度的解剖学变化
DOI：
10.1093/treephys/tpab017
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发表时间：
2021-02-08
期刊：
影响因子：
4
通讯作者：
Li, Chunyang
中科院分区：
文献类型：
--
作者：
Liu, Miao;Liu, Xiucheng;Li, Chunyang
叶片结构和光合作用的协同调节对于耐盐性至关重要。然而，植物性和无机氮源如何改变盐胁迫依赖性光合作用仍然未知。在盐胁迫条件下结合硝酸盐 NO3- 和铵 NH4+ 供应对青杨雌性和雄性的叶片解剖特征和光合作用进行了研究，以阐明其潜在机制。在盐胁迫的雌性中，我们观察到叶肉海绵细胞密度增加，叶绿体密度减少，邻近细胞间隙的叶绿体表面积（S-c/S）减少，单位横截面宽度的叶肉细胞面积（S/W）增加，从而导致叶肉导度（g（m））和光合作用抑制，特别是在NH4+下 供应。相反，具有较大叶肉栅栏组织厚度和叶绿体密度但海绵细胞密度较低的雄性具有较低的S/W和较高的S-c/S，以及较高的g(m)和光合作用。与提供 NO3- 的雌性相比，饲喂 NH4+ 的雌性具有较低的穿过细胞壁的 CO2 电导和垂直于细胞壁的基质电导，但来自细胞壁的叶绿体电导 (g(cyt1)) 高于提供 NO3- 的雌性，而在盐胁迫下，当提供 NO3- 而不是 NH4+ 时，雄性具有较高的叶绿体电导和较低的穿过细胞壁的 CO2 电导。这些发现表明，在两种类型的氮供应下，应对与叶片解剖结构和 g(m) 相关的盐胁迫的性别特异性策略，这可能有助于性别特异性的二氧化碳捕获和生态位隔离。
Synergistic regulation in leaf architecture and photosynthesis is essential for salt tolerance. However, how plant sex and inorganic nitrogen sources alter salt stress-dependent photosynthesis remains unknown. Leaf anatomical characteristics and photosynthesis of Populus cathayana Rehder females and males were investigated under salt stress conditions combined with nitrate NO3- and ammonium NH4+ supplies to clarify the underlying mechanisms. In salt-stressed females, we observed an increased mesophyll spongy cell density, a reduced chloroplast density, a decreased surface area of chloroplasts adjacent to the intercellular air space (S-c/S) and an increased mesophyll cell area per transverse section width (S/W), consequently causing mesophyll conductance (g(m)) and photosynthesis inhibition, especially under NH4+ supply. Conversely, males with a greater mesophyll palisade tissue thickness and chloroplast density, but a lower spongy cell density had lower S/W and higher S-c/S, and higher g(m) and photosynthesis. NH4+-fed females had a lower CO2 conductance through cell wall and stromal conductance perpendicular to the cell wall, but a higher chloroplast conductance from the cell wall (g(cyt1)) than females supplied with NO3-, whereas males had a higher chloroplast conductance and lower CO2 conductance through cell wall when supplied with NO3- instead of NH4+ under salt stress. These findings indicate sex-specific strategies in coping with salt stress related to leaf anatomy and g(m) under both types of nitrogen supplies, which may contribute to sex-specific CO2 capture and niche segregation.