Proteomic Analysis Of Elongation Internode Of Maize Inbred Lines

Accompanying the plant density increasing in the field, the risk of lodging isincreasing simultaneously, especially in the tropical and subtropical area, it often hasextreme climate in maize growing season. Out of abiotic stress, several traits in maizeincluding plant height, ear height, stalk tenacity, the number of aerial root andinsertion directivity, etc., also play an important role on influencing lodging. Earheight is comprised of internode number and the total length of the prolonginginternode under ear, and directly decides the center of plant gravity, so it has asignificant relationship with lodging in the field. For the prolonging internode underear, the length of each internode from the first prolonging internode is increasinggradually for inbred lines and hybrids, and it play an important role on deciding earheight.In order to better understand just how internodes morphological distinction relate toplant proteins in maize (Zea mays L.) internodes during primary stage of elongation.This study utilized eight common maize inbred lines (Zong3, Yu87-1, Xun9058,Xun928, Chang7-2, Zheng58, P2and A50) by proteomic composition of individualinternodes to explore the regulatory factors key for internodes extension. Thepurposes of study were to:1) identify different expressing proteins between theseventh to ninth developing internodes;2) analyze the metabolize pathway ofhormones regulation in the biological progression of internode prolong in maize.Analysis of protein accumulation change patterns revealed that total66proteins wereexisted significant differences, which46key proteins closely associated withhormones signal transduction could be involved in internodes elongation. Results ofthis study confirm that46key proteins regulated hormones coordinate changes wereconsistent with cell growth and division in stalk developmental process. Furthermore,different regulatory networks occur in different inbred lines either in differentinternodes of one inbred lines. Those consequences provide theoretical basis for better understanding of the molecular and physiological processes and interactions. Themain results were showed as follow：1, Internode final length: each length of internode was compared with each averagewhich got from twenty individual plants, and the length of the internode showed agradual increase from number7th to9th in the eight inbred lines in the field.2,2-DE gel analysis results: total protein of7,8,9internode in8inbred lines wereseparated by strip (24cm, PH4-7). After comparing the reproducible spots in eachsample one by one, we found that300±17、522±10、493±11、383±9、449±10、468±19、328±13、476±15spots were identified in inbred lines Zong3, Yu87-1, Xun9058,Xun928, chang7-2, zheng58, P2and A50, respectively. By further quantitative andcomparative analysis of those spots by PDQuest8.0software among internodes7through9of each inbred lines, we found in total66that15,13,6,7,3,7,10and5spots have differentially accumulated more than twofold in8inbred lines,respectively.3, Functional analysis results: there were same enzymes which called6-phosphofructokinase, triose phosphate isomerase, phosphoenolpyruvic acidhydratase, isocitrate dehydrogenase, glutathione dehydrogenase, L-ascorbic acidperoxidase, methionine synthase, adenosine methionine transferase,hydroxyacylglutathione hydrolase participate in the internodal elongation andhormonal regulation. These enzymes through interaction and coordinating role topromote stem elongation.