RESUMO
Alligator weed, Alternanthera philoxeroides (Mart.) Grisb, is an amphibious plant with long thick fleshy roots that develop from adventitious roots under drought conditions. To clone differentially-expressed genes from the roots of A. philoxeroides we applied both mRNA differential display and rapid amplification of cDNA ends techniques. A cryptogein-like gene of A. philoxeroides, designated as ApCL, was cloned. On the basis of semi-quantitative RT-PCR analysis results, we demonstrated that the ApCL gene was upregulated under drought and salt stress conditions. After ApCL was transferred to Pichia pastoris GS115 and its resistance to drought and salt then increased by >100 %. Therefore, the ApCL gene of A. philoxeroides was likely involved in drought and salt tolerance responses.
Assuntos
Amaranthaceae/genética , Amaranthaceae/fisiologia , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Sequência de Aminoácidos , Secas , Proteínas Fúngicas , Modelos Moleculares , Dados de Sequência Molecular , Pichia/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
To establish a successful in vitro plant regeneration system in Alternanthera philoxeroides (Mart.) Griseb, an orthogonal design was used to investigate the effects of three factors (plant growth regulators, explant types and dark treatment in initial-stage), each having three levels. The effects of these factors and levels on callus induction and shoot regeneration were quantitatively evaluated by analysis of variance. The experimental results showed that the callus induction was significantly affected by 2, 4-dichlorophenoxyacetic acid (2, 4-D), and shoot differentiation from subcultured pieces of callus was enhanced mostly by dark treatment in initial-stage. The optimal conditions for callus induction are obtained from the stem explants cultured on semi-solid Murashige and Skoog (MS) medium plus 2.2 µM BA and 2.2 µM 2, 4-D, with 20 days dark treatment in initial-stage. The highest frequency of shoot regeneration is obtained from the calli cultured on semi-solid MS medium plus 8.8 µM BA, without dark treatment in initial-stage.