Studies On Specified Inclusion Of Dune Reed Protects Maize Seedling Leaf Photosynthesis And Protein Oxidation Injury Under Drought Stress

This paper studied the effects of the PAAC on relative water content, main photosynthetic parameters, chlorophyll fluorescence parameters and Protein Oxidation Injury of two maize varieties in Seedling stage under well-watered and drought stress via sand culture experiment. With the leaf relative water content (RWC) evaluate the change of plant tissue water, at the same time measured the chlorophyll fluorescence parameters and photosynthetic indicators to research the changes in law of photosynthetic activity and light use efficiency of maize seedlings under drought stress, and explore the role of PAAC on affecting photosynthesis processes of plant. Compared with the betaine treatment, to study the effects of the inclusion on protein oxidation injury. A part of the amino acid residues were oxidized carbonyl first, carbonyl protein accumulation in the body as the continuing of oxidation. The protein carbonyl content can reflect the level of protein oxidative damage. Main access to the following results:1. Measuring the photosynthetic parameters of leaf, found that PAAC can effectively reduce the declining of leaf net photosynthetic rate in the moderate drought stress, but it has no significant effect on the stomatal conductance. Speculated it may mainly affect the non-stomatal factors of photosynthesis. With the research of chlorophyll fluorescence parameters may reflect the energy utilization in photosynthetic reaction center and changes of biological activity when the plants under drought stress. The results showed that:Under the drought stress, the Fv/Fm and Yield values decline emerged of all leaves, but the Fv/ Fm, Yield values of maize seedlings treated by PAAC were significantly higher than the control, indicates that with the worsening of drought, PSâ…¡efficient of convert light into chemical energy of leaves sprayed by PAAC higher than the control, it shows that PAAC can protect the photochemical activity of PSâ…¡on thylakoid membrane. At the time, the trend of qP and ETR were similar with the Fv/Fm, PAAC treatment reduced the decrease of these parameters. The qP higher, the antenna pigments absorb light energy for photochemical electron transmitting higher, that is to say the photosynthetic electron transport activity of PSâ…¡was higher. The ETR was higher shows the rate of relative photosynthetic electron transport was higher. Further confirmed that PAAC can maintain the level of cell metabolism and enhance the plant's drought resistance2. Measuring the carbonyl content of maize protein by the method DNPH and found that exogenous spraying PAAC solution can significantly reduce the increasing of carbonyl content of plant leaves protein under drought stress. It suggest that the inclusion can be effectively reduced the level of protein oxidation injury in plants under drought stress, and simultaneous measure the leaf RWC, found that the relative water content of PAAC-treated seedlings are higher than others, which shows PAAC reduce water loss. Because PAAC and betaine have the same effect in the above two results. It shows that PAAC and betaine which has been recognized to protecting material for plant have similar function in plant body.