The plant-specific NAC transcription factors control various biological processes, including plant development and stress responses. We have isolated an ANAC032 gene, one of the NAC transcription factor family, which was highly activated by multi-abiotic stresses, including high salt and drought in Arabidopsis. Here, we generated transgenic plants constitutively expressing ANAC032 and its knockout to identify the functional roles of ANAC032 in Arabidopsis under abiotic stress responses. The ANAC032-overexpressing plants showed enhanced tolerance to salinity and drought stresses. The anac032 knockout mutants were observed no significant changes under the high salt and drought conditions. We also monitored the expression of high salt and drought stress-responsive genes in the ANAC032 transgenic plants and anac032 mutant. The ANAC032 overexpression upregulated the expression of stress-responsive genes, RD29A and ERD10, under the stresses. Thus, our data identify that transcription factor ANAC032 plays as an enhancer for salinity and drought tolerance through the upregulation of stress-responsive genes and provides useful genetic traits for generating multi-abiotic stress-tolerant forage crops.

Forage crop management is severely challenged by global warming-induced climate changes representing diverse a/biotic stresses. Thus, screening of valuable genetic resources would be applied to develop stress-tolerant forage crops. We isolated two NAC (NAM, ATAF1, ATAF2, CUC2) transcription factors (ANAC032 and ANAC083) transcriptionally activated by multi-abiotic stresses (salt, drought, and cold stresses) from Arabidopsis by microarray analysis. The NAC family is one of the most prominent transcription factor families in plants and functions in various biological processes. The enhanced expressions of two ANACs by multi-abiotic stresses were validated by quantitative RT-PCR analysis. We also confirmed that both ANACs were localized in the nucleus, suggesting that ANAC032 and ANAC083 act as transcription factors to regulate the expression of downstream target genes. Promoter activities of ANAC032 and ANAC083 through histochemical GUS staining again suggested that various abiotic stresses strongly drive both ANACs expressions. Our data suggest that ANAC032 and ANAC083 would be valuable genetic candidates for breeding multi-abiotic stress-tolerant forage crops via the genetic modification of a single gene.

Streptomyces padanus IA70-5 has been shown to be a promising biological control agent for the suppression of pepper anthracnose. In this study, we assessed the potential use of strain IA70-5 as a biological control agent for Phytophthora blight caused by Phytophthora capsici. Strain S. padanus IA70-5 was found to inhibit the mycelial growth and zoosporangium formation of P. capsici causing Phytophthora blight on pepper plants. In experiments with hot pepper fruit, IA70-5 suppressed the progression of Phytophthora rot by over 90% in pre-inoculated treatments with culture suspension. In experiments with 60-day-old pepper plants, IA70-5 suppressed Phytophthora blight by over 90%. These results demonstrated the potential for S. padanus IA70-5 to provide a practical biological agent for the control of Phytophthora blight in the field.

고추에 큰 피해를 일으키는 탄저병에 대한 강한 길항력이 있는 세균을 선발하기 위해 선행연구에서 식물뿌리 시료로부터 분리하여 보관중인 세균들을 대상으로 검정에 사용하였다. 총 457균주로부터 IA70-5균주를 최종 선발하였고, 16S rDNA 염기서열 분석을 통해 Streptomyces padanus로 동정하였다. S. padanus IA70-5는 색소를 분비하지 않고 운동성이 없으며 전형적인 Streptomyces속에 속하는 세균들처럼 나선형의 형태를 이루고 있었다. S. padanus IA70-5 균주는 in vitro에서 Colletotrichum acutaum의 균사생장, 포자발아, 그리고 부착기 형성을 효과적으로 억제하였다. 실내 고추 과실에 대하여 병원균 접종 전 IA70-5 배양액 처리 시 약 90%의 탄저병 억제효과를 나타내었다. 본 연구결과를 통하여 길항방선균 S. padanus IA70-5는 고추 탄저병을 억제하는 효과가 있음을 확인하였다.