Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions
Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions
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DOI：
10.1071/fp06078
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发表时间：
2006-01-01
影响因子：
3
通讯作者：
Altmann, Thomas
中科院分区：
文献类型：
--
作者：
Buessis, Dirk;von Groll, Uritza;Altmann, Thomas
过量表达sdd1(气孔密度和分布)基因的转基因拟南芥植株的气孔密度降低到40%，而sdd1-1突变体的气孔密度增加到野生型的300%。在生长期间的光照条件下，超强型和sdd1-1突变体的CO2同化速率和气孔导度与野生型相比没有变化。较低的气孔密度通过增加气孔开度来补偿，相反，增加的气孔密度通过减小气孔开度来补偿。在高光强下，SDD1超表达植株的同化率和气孔导度降低到野生型植株的80%。分别对气孔下方区域和无气孔斑块进行分析。无气孔区的最大荧光产量(F(V)/F-m)和光系统II的量子效率(Phi PSII)显著低于气孔区。在气孔下方区域，F-v/F-m和phi PSII与野生型叶片的水平相同。在高光强下，与野生型相比，超表达株的光化学猝灭(QP)降低。但无气孔区的qp下降幅度明显大于气孔下叶肉区。在高CO2分压和高光强条件下，SDD1超表达株的CO2同化速率没有达到野生型水平。这些结果表明，在强光下，由于限制了远离气孔的区域的二氧化碳排放，SDD1超表达株的光合作用降低。
Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (F (v)/ F-m) and quantum yield of photosystem II (Phi PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, F-v / F-m and Phi PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.