Of Bamboo Leaf Senescence Mechanism

This paper had dealt with the study on Pseudosasa amabilis(McClure)Keng, Pseudosasa amabilis var.convexa Wan et Ye, Pleioblatus Simonii(Carriere)Nakai.by measureing a series of indexes on the leaves of plants ,come to discuss the reasons of consenescence on bamboo leaves.the general conlusions on consenescence of bamboo leaves were drawn as follows:1 .In generally,the content of chlorophyll in the bamboo leaves come to decrease along with consenescence progress, chlorophyll declining reflects that the ability of photo-synthesis on the bamboo leaves is descending.The ability of photo-synthesis de -scent is an important factor to decide when consenescence symptom begins.Moreove -r, the chlorophyll of the bamboo leaves declines faster during the period of bamboo blooming than other periods. Therefore , when the bamboo blooms,the consenescen -ce of bamboo leaves will be more severe.2. Generally speaking, SOD,POD activity in mature leaves is higher than new on -es. SOD, POD activity increases during the period of bamboo blooming.By the comparison of the changes in POD, SOD activity, POD can reflect better than SOD in the aspect of bamboo leaves consenescence.3. RPP in bamboo leaves goes up in the process of consenescence, when bamboo blooms, the RPP of leaves goes up quickly.Therefore, the bamboo efflorescence will accelerate the consenescence of leaves.4. At the aspect of incretion, IAA, GA, ZR represses the consenescence of leaves, ABA promotes the consenescence of leaves. In the progress of consenescence in bamboo leaves, on the whole, ABA contents in bamboo leaves rises.IAA, GA, ZRcontents descend.5. Seeing from the activity of DNase and RNase,they increase at the progress of consenescence in bamboo leaves. At the period of bamboo bloom, the activity of RN-ase , DNase runs more quickly.So we can draw a conclusion that the bamboo efflorescence promotes the activity of DNase and RNase.By comparison,the change of RNase activity is more obvious than that of Dnase , therefore, the change of RNase activity can reflect the bamboo consenescence better.6. When bamboo leaves begin to decline, the protein of leaves decreaese, this ma -in reason is the function of the protein-fallen enzyme.For the difficulty of measure -ment and authenticate,in addition, gene expresses complexity at the progress of leave -s consenescence.I can only authenticate two kinds of protein-fallen enzym{ papain-(carboxymethly),aspar- tate transcarbamylase,R chain}. So bamboo leaves consenesce -nee still needs further research in the aspects of the protein.7. IAA in bamboo leaves has a negative feedback relation with POD, SOD ,inthe whole,the order is IAA>GA>ZR. ABA has a positive feedback relation with POD, SOD activity .IAA has obvious negative feedback relation with ABA. aspartate8 .To sum up, bamboo leaves consenescence is alike with other plant leaves .But, there is also something different ,it has something to do with the physiology character -ristic of bamboo and environment factors, such as bamboo efflorescent variety,rejuv -enation, physiology age and grow age etc.