Regeneration System Construction Of Salsola Collinaand Study On Transfer Carbonic Anhydrase?CA6 To Rice

As the major producers on the earth,plants provide organics through photosynthesis.Based on differences of carbon dioxide assimilationplants can be divided into C₃,C₄ and CAM plants.C₄ plants have special structures to maintain more efficient photosynthetic efficiency.C₄ plants are unique in their physiological structure and gene expression.Studying of typical C₄ plants give an insight into the C₄ photosynthetic regulatory network.It is an effective way to improve the photosynthetic efficiency of C₃ plants by referring to the physiological characteristics of C₄ plants and differential gene expression.Salsola is a typical C₄ model plant.So,the establishment of a regenerated system of Salsola brassicae is the basis for its photosynthetic studies.In this experiment,S.passerina and S.collina are used to tissue culture.The experiments were mainly carried out from the hormone ratio,types of media,and selection of explants.Through the exploration of various hormone ratios,selection of explants,and culture media,In the aspect of callus culture of Salsola marinae,it was concluded that6-BA and 2,4-D are the best combinations for tissue culture.The Salsola passerina Bunge callus formation rate was as high as 84.6%if 6-BA 0.5 mg/l and 2,4-D 2.5 mg/l used in culture media.The S.collina Pall callus formation rate was as high as 88%with 6-BA 0.5 mg/l and 2,4-D 2.0 mg/l.In the callus differentiation,the study was mainly carried out under various hormone ratios and gradients under light conditions of 8 h/16 h.however,the experiment did not form seedling.Instead,five different callus tissue wered emerged.Roots were differentiated on MS medium with 6-BA 0.2 mg/l and NAA 0.1 mg/l.Rice is a typical C₃ plant,imporving rice yield is a necessary requirement for addressing food security issues.It is one of effective ways to increase the photosynthetic efficiency by transfering C₄plant-related photosynthetic enzymes in rice;Findingtissue-specific promoters inrice can provide an effective tool for transgene-specific expression.This experiment was conducted in two aspects.The first experiment was to clone the GbSLSP promoter,a guard cell-specific promoter,fromGossypium barbadense,then construct a GUS expression vector.The GUS expression vector was transformed into rice.In the T₁ generation,GUS gene expression was found in rice leaf guard cells,but the expression level was weak.Another way,At?CA6 overexpression vector was transformed into rice to study related physiological functions.In the T₁ generation,multipleoverexpressing lines were detectde by PCR.In the T₂ generation,three OE lines were randomly selected for RT-PCR.The results showed that?CA6 was detected in the three lines.Physiological determination of the T₂ plants of transgenic rice was subsequently performed.Compared with the wild type,the net photosynthetic rate increased and respiration rate decreased,there was no significant difference in the physiological indexes between the above-ground and underground parts of the plant,such as dry and fresh weight,and plant height.