N-3-oxo-hexanoyl-homoserine lactone, a bacterial quorum sensing molecule, plays an important role in plant salt tolerance
摘要
N-acyl-homoserine lactones(AHLs) are the quorum sensing(QS) signal molecules to coordinate the collective behavior in a population in Gram-negative bacteria. Recent evidences demonstrate their roles in plant root growth and defense responses. In this present,we show that the treatment of plant roots with N-3-oxo-hexanoyl-homoserine lactone(3OC6-HSL),one molecule of AHLs family,resulted in enhanced salt tolerance in Arabidopsis,wheat and rice. The genetic analysis revealed that the growth inhibition phenotype in the length of primary roots,the fresh weight and the height of seedlings under salt stress condition were significantly improved by 3OC6-HSL. The contents of chlorophyll were increased and the Na~+/K~+ ratios were decreased by 3OC6-HSL in Arabidopsis,wheat and rice under salt stress condition. The level of proline were raised and the expression of proline biosynthesis related genes AtP5CS,TaP5CS and the proline transport gene Ta PT were upregulated by 3OC6-HSL under salt stress condition,which suggested that the proline biosynthesis and transportation may be involved in 3OC6-HSL-mediated plant salt tolerance. q RT-PCR analysis showed that the expression of some salt-responsive genes including ABA-dependent genes RD22 and COR15 a,osmotic responsive gene ADH,ion-homeostasis related genes SOS1 and SOS2 were induced by 3OC6-HSL in Arabidopsis. But only the expression of COR15 a was upregulated with a stronger induction by 3OC6-HSL than by Na Cl under salt stress condition. 3OC6-HSL had no effect on the expression of ABA-independent gene ERD1 under salt stress condition. These results indicated that ABA-dependent salt resistant pathway might involve in AHL-induced salt tolerance. In summary,genetic,physiological and molecular evidences showed that 3OC6-HSL plays an important role in plant salt tolerance. It provides a new insight into the plant-microbe inter-communication.
N-acyl-homoserine lactones(AHLs) are the quorum sensing(QS) signal molecules to coordinate the collective behavior in a population in Gram-negative bacteria. Recent evidences demonstrate their roles in plant root growth and defense responses. In this present,we show that the treatment of plant roots with N-3-oxo-hexanoyl-homoserine lactone(3OC6-HSL),one molecule of AHLs family,resulted in enhanced salt tolerance in Arabidopsis,wheat and rice. The genetic analysis revealed that the growth inhibition phenotype in the length of primary roots,the fresh weight and the height of seedlings under salt stress condition were significantly improved by 3OC6-HSL. The contents of chlorophyll were increased and the Na~+/K~+ ratios were decreased by 3OC6-HSL in Arabidopsis,wheat and rice under salt stress condition. The level of proline were raised and the expression of proline biosynthesis related genes AtP5CS,TaP5CS and the proline transport gene Ta PT were upregulated by 3OC6-HSL under salt stress condition,which suggested that the proline biosynthesis and transportation may be involved in 3OC6-HSL-mediated plant salt tolerance. q RT-PCR analysis showed that the expression of some salt-responsive genes including ABA-dependent genes RD22 and COR15 a,osmotic responsive gene ADH,ion-homeostasis related genes SOS1 and SOS2 were induced by 3OC6-HSL in Arabidopsis. But only the expression of COR15 a was upregulated with a stronger induction by 3OC6-HSL than by Na Cl under salt stress condition. 3OC6-HSL had no effect on the expression of ABA-independent gene ERD1 under salt stress condition. These results indicated that ABA-dependent salt resistant pathway might involve in AHL-induced salt tolerance. In summary,genetic,physiological and molecular evidences showed that 3OC6-HSL plays an important role in plant salt tolerance. It provides a new insight into the plant-microbe inter-communication.
引文