Tham khảo tài liệu 'advances in photosynthesis fundamental aspects part 16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 442 Advances in Photosynthesis - Fundamental Aspects 1988 Ward et al. 1995 . As an important player in stomatal regulation the I Kin is an indirect target of polyamine action. A number of studies have shown that I Kin-inhibiting processes or factors often inhibit stomatal opening Assmann 1993 . Liu et al. 2000 using patch-clamp analysis demonstrated that intracellular application of polyamines inhibited the inward K1 current across the plasma membrane of Vicia faba guard cells and modulated stomatal movement. Changes of free Ca2 in the cytoplasm of guard cells are involved in stomatal aperture closure. In the Spm-deficient mutant Arabidopsis seems to be impaired in Ca2 homeostasis which affects the stomatal movement and that this inhibited effect was restored by application of exogenous Spd in the mutant plants Yamaguchi et al. 2007 . In addition it has been reported that polyamine-induced ROS scavenging is an essential effect and stimulated stomatal closure lower water loss upon dehydration which may function collectively to enhance dehydration tolerance Pei et al. 2000 Bright et al. 2006 . These findings suggest that polyamines target KAT1-like inward K1 channels in guard cells and modulate stomatal movements providing a link between stress conditions polyamine levels and stomatal regulation. Photosynthetic pigment Chlorophyll Chl is a molecule substance that plays an important role in photosynthesis for the plant growth process such as light absorption and combination with protein complex transfer the energy into carbohydrate Meskauskiene et al. 2001 . A variety of reports indicate that changes in chlorophyll levels of plants may decrease in response to environmental factors or leaf senescence Sfichi-Duke et al. 2008 Munzi et al. 2009 . Aliphatic polyamines PAs are involved in the delay loss of chlorophyll and lead to an increased efficiency of light capture resulting in the improvement of net photosynthetic rate but the molecular mechanism is not clarified.
