Comparison And Analysis Of Physiological And Biochemical Responses As Well As Protein Expression Profile Among Different Species Of Grass Pea

Grass pea(Lathyrus sativus L.)has many advantageous biological and agronomic characters as well as extensive tolerance to adverse environment,in spite of neurotoxin ODAP.The biological characters of grass pea in field,ODAP content,physiological and biochemical responses combined with protein expression profile were studied in this thesis,which would provide new clues to the research and development of grass pea.The key results are as follows:1 Thirty species of grass pea were planted in the field.The differences in ODAP content and the morphologic characteristic of both flowers and seeds were compared among different species. The results showed that:1)ODAP content was changeable,and even in the same species.It was highest in 8#,and lowest in 6# and 9#;2)Flowers and seeds of 6#,7# and 9# were quite different from other varieties,and the resistance to waterlogging of 6# and 9# was less strong especially.2 The physiological and biochemical responses among three representative varieties 7#,8#, 9# were studied.The results showed that,1)basal contents of soluble sugar,proline content,SOD and POD were the highest in 8#,lower in 7# and lowest in 9#;2)8# was thicker in stems and roots,bigger in leaf size,higher in 1000-grain weight than 7# and 9#.All above suggested that 7# and 8# were superior to 9# in the aspects of stress resistance,forage yield and grain yield.3 Anaysis of 2-DE showed that there were 21,41 and 36 differentially expressed protein spots in 7#,8# and 9#,respectively.Eight differentially expressed protein spots between the gel of 8# and 9# were identified by MALDI-TOF/TOF and LTQ(LC-MS-MS)and their function were analyzed by searching MASCOT,NCBI database and SWISS-PROT.The results showed that:1) 20 kDa chaperonin(chloroplast precursor),disappearing in 9#,was normally coordinated with cpn60 family,and promoted the assembly of Rubisco subunit so as to CO₂ fixation; Fructose-bisphosphate aldolase(FDA,chloroplast),down-regulation in 9#,was related to increasing the production of starch and sucrose,and Oryza sativa Japonica Group cDNA clone OSJNEb05K22 5' mRNA sequence shared 73%identity to PSI-E(photosystemâ… reaction center subunitâ…¥,chloroplast precursor).Obviously,these three proteins were related to formation of carbohydrates,and thus changes of expression in 9# may be related to the lower forage yield and grain yield.2)Nascent polypeptide-associated complex NAC and ribonucleoprotein(RNP) different in migration between 8# and 9# were both likely to due to post-translational modification. NAC was one kind of auxiliary transcription factor and had many functions.RNP acted at the transcription level,and related to lots of cellular processes.Probably both of them played roles in alternative expression of gene in species 7#,8# and 9#,and led to great differences in toxin content,stress resistance,forage yield and grain yield.4 The drought-resistant responses as well as the relationship between stress and ODAP content were studied.The effect of drought on toxin content was lower than microelement such as Fe²⁺,and it was likely that ODAP played few roles in stress resistance.In summary,there were obvious differences in ODAP content,stress resistance,forage yield and grain yield between high-toxic species 8# and low-toxic 9#,which might be the results of alternative expression of related genes,and further study was necessary for understanding the inherent relevant better.