Evaluation Of Sulfur Deficiency Tolerance And Expression Analysis Of Transferred Gene In SsBHMT Transgenic Arabidopsis Thaliana

Sulfur is an essential macroelement in plant nutrition. A lack of sulfate supplyeffects the harvest and nutritional quality of crop plants. The sulfur-containing α-aminoacid methionine is an essential amino acid. Because mammals do not produce methioninedenovo, so it must be provided by the external access. The level of methionine often limitsthe nutritional value of crop plants. Apart from its role of the nutritional value, methionineis a central role in the initiation of mRNA translation and protein constituent, it indirectlyregulates a variety of cellular processes. In plants methionine is not only a fundamentalmetabolite, but also as the substrate of S-adenosylmethionin synthetase (SAMS)participates in S-adenosylmethionine (SAM) synthesis. SAM is the primary biologicalmethyl group donor, which is biosynthesis lignins, ethylene, polyamine, osmotic regulator.SAM relate with resistance.Betaine-homocysteine-S-methyltransferase(SsBHMT) is amethyl metabolism enzyme. In animals and microbes, this enzyme can catalyze betaine tohomocysteine form methionine. Therefore, we analyed the sulfur deficiency tolerance ofSsBHMT transgenic Arabidopsis, expression analysis of transferred gene, the content ofmethionine. It provided theoretical basis for studying the synthesis and metabolicmechanisms of methionine in plants, the SsBHMT gene with resistance of plants. The mainresults were shown as follows:1. Phenotype results showed that the transgenic plants exhibited less discoloration incomparison to control plants under sulfur deficiency stress;Whether or not with betaine, thetransgenic plants exhibited more wooded in comparison to control plants and root densitywere greater than wild type under normal condition; The root length were greater than wildtype under sulfur deficiency stress and normal condition with betaine.2.Physiological and biochemical analysis showed that the activity of SOD was higherthan wild–type under normal condition and sulfur deficiency stress; The chlorophyllcontent was higher than wild–type plants, the content of MDA was lower than wild–typeunder sulfur deficiency stress; The activity of SOD and chlorophyll content were higherthan wild–type under sulfur deficiency stress with betaine.3.Immune analysis expression of the transferred gene showed that the target proteinhad no obvious change under sulfur deficiency stress and the same condition with betaineaddition.Western blot do not detect significant change about the target protein at the different time points of the sulfur deficiency and salt stress. The expression of the targetprotein had no obvious change under50mmol/L NaCl stress,while the75mmol/L NaCltreatment makes the target protein decreased significantly compared with the normal. Afteradding betaine, the expression of the target protein decreased under normal condition. Theprotein had no obvious change under50mmol/L NaCl stress with betaine addition,whilethe protein increased under75mmol/L NaCl with betaine addition.4.The methionine content was measured between the seed of the wild–type andtransgenic plants. The amplitude of methionine content variation in transgenic plants wasgreated than that in wild-type. Under normal condition the methionine content intransgenic plants was higher than that in wild-type.