Search

The [Ca.sup.2+] signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CAM) isoforms are activated by infection or pathogen-derived elicitors and participate in [Ca.sup.2+]-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 rain by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular [Ca.sup.2+] level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA.independent signal transduction chain leading to disease resistance.

Empirical evidence suggests that the family system is under pressure in the United States. This evidence includes but is not limited to a significant increase in out-of-wedlock childbearing by teenagers, an increase in the number of children living in families below the poverty level, lack of available health care to large numbers of children and families, and a rising number of children dropping out of school. The authors offer an analysis of the problems facing families, and a national policy model for children and families is proposed., Significant social, economic, and demographic changes have occurred in families over the last three decades. These changes have had a pronounced impact on children; many now live with only one [...]

This study reports findings on factors associated with children who terminate psychotherapy prematurely. The sample was composed of 45 children, with an average age of 13.5 years. It was found that children are more likely to remain in treatment if the therapist is perceived as professional and caring, and if the treatment plan is adequately explained., Identifying children who fail to complete psychotherapy is critical for two reasons: Those who drop out do not receive needed clinical services; and clinics have invested a great deal of [...]