Nutritional Composition And Proteomics Study On Stress Response Of Five Wild Species Amygdalus Plants Seeds

Amygdalus plants(APs)are the original materials for obtaining good resistance genes in the breeding of almond species for their stress resistance to drought,cold,saline and alkali environment.However,there were few reports on the stress resistance of wild APs resources from the level of proteomics.The nutritional composition and nutritional values of 5 APs such as A.pedunculata Pall.(APP),A.mogolica(Maxim.)Yü(AMY),A.tangutica Korsh.(ATK),A.ledebourianna Schleche.(ALS)and A.triloba(Lindl.)Richer(ATR)were evaluated by analyzing the crude fat,crude protein,dietary fiber,carbohydrate,mineral element and vitamins of theie kernels.The resistance mechanism of various stress factors in natural ecological environment(referred to as habitat stress)in the level of proteomics of 5 APs species were explored to obtain the valuable stress-resistant biomarker protein,in order to provide precious stress-resistant genetic resources for further research on Amygdalus plants.The results are as followed:1.Evaluation on the nutritional composition and potential of APs plants seedsHigh contents of oil(34.97~51.22g/100g),protein(19.44~27.56 g/100g)and dietary fiber(9.09~12.48g/100g)were found in the kernels of APP,AMY,ATK,ALS and ATR,Total sugar,reducing sugar,various mineral elements(phosphorus,potassium,calcium,magnesium,zinc,manganese,copper and iron)and vitamins(including vitamin E,vitamin C,niacin,nicotinamide and vitamin B2)were also to be detected in these kernels.The content of glutamic acid,aspartic acid and arginine in the general hydrolyzed amino acids of APs kernels varied from 5.78 to 7.76 mg/100 g,2.26 to 3.67 mg/100 g and 1.72~ to 2.53 mg/100 g,which were higher than those of the other hydrolyzed amino acid,indicating that the kernels of 5 APs have high nutritive value to be developed and applied.2.Analysis of the habitat stress-responsive proteomics and its possible mechanism of 5 APs species seedsThere were 88 proteins relating to stress response in kernels of APP,AMY,ATK,ALS and ATR.These consensus proteins were annotated and can be divided into 4 different functional groups: antioxidant enzymes,enzymes/proteins involved in metabolic processes(glycolytic,tricarboxylic acid cycle,proteolysis and cysteine metabolism,transcriptional regulation,detoxification,etc.),proteins involved in signal transduction,and stress proteins(mainly heat shock proteins and chaperones).These proteins respond the stress environment by participating intracellular redox or protein folding and maintaining cell redox homeostasis,which may be the common stress resistance mechanism of the APs species.These responds reflects the same genetic composition and homologous of APs species.3.Analysis of differential proteomics and habitat stress-resistant marker proteins in kernels of 5 APs speciesIn order to analyze the differences of habitat stress-responsive protein groups and their possible mechanisms,we compared the differential proteomics in kernels of APP to AMY,ATK,ALS and ATR kernels.The results showed that the numbers of habitat stress-responsive proteins in kernels of APP and ATK were the highest,and their numbers were about 91 species,which was much higher than those of the habitat stress-responsive proteins numbers of ATK,ALS and ATR(varied from 36 to 39).Among the habitat stress-responsive differential proteins in kernels of APs species,most of the differential proteins were down-regulated in APP kernels.The significant difference in habitat stress-responsive protein groups of 5 APs species may be related to differential ecological and environmental conditions The possible mechanisms of habitat stress-responsive differential proteins were mainly related to the scavenging abilities of antioxidant enzymes for reactive oxygen species,the process of protein folding by heat shock proteins and their chaperones,the energy and synthetic raw materials for defense response to stress provided by the glucose metabolism and energy metabolism,the process of protein hydrolysis and amino acid metabolism,transcriptional regulation of protein expression,the process of maintaining intracellular redox homeostasis,detoxification and defense mechanisms against fungi and viruses.The protein-zinc-binding dehydrogenase family proteins(AT5G16990)and thioredoxin H-type 1(TRX1),which showed significant differential expression among APs species,are expected to be the habitat stress-resistant biomarker protein for the APs species.