scholarly journals Conversion of compatible plant-pathogen interactions into incompatible interactions by expression of the Pseudomonas syringae pv. syringae 61 hrmA gene in transgenic tobacco plants

2000 ◽  
Vol 23 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Songhai Shen ◽  
Qingshun Li ◽  
Sheng-Yang He ◽  
Kenneth R. Barker ◽  
Debao Li ◽  
...  
2003 ◽  
Vol 143 (3) ◽  
pp. 349-357 ◽  
Author(s):  
SORAYA C M LEAL-BERTIOLI ◽  
ALETEIA V PASCOAL ◽  
PATRICIA M GUIMARAES ◽  
MARIA F GROSSI SA ◽  
REJANE L GUIMARAES ◽  
...  

2004 ◽  
Vol 17 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Georgina Fabro ◽  
Izabella Kovács ◽  
Valeria Pavet ◽  
László Szabados ◽  
María E. Alvarez

Accumulation of free L-proline (Pro) is a typical stress response incited by osmotic injuries in plants and microorganisms. Although the protective role of Pro in osmotic stress is not well understood, it is thought to function as compatible osmolyte or as a scavenger of reactive oxygen species (ROS). Here we show that, in Arabidopsis thaliana, Pro biosynthesis can be activated by incompatible plant—pathogen interactions triggering a hypersensitive response (HR). Pro accumulates in leaf tissues treated with Pseudomonas syringae pv. tomato avirulent strains (avrRpt2 and avrRpm1) but remains unchanged in leaves infected with isogenic virulent bacteria. Incompatible interactions lead to transcriptional activation of AtP5CS2, but not AtP5CS1, encoding the rate limiting enzyme in Pro biosynthesis pyrroline-5-carboxylate synthase (P5CS). AtP5CS2:GUS and AtP5CS2:LUC transgenes were induced inside and around the HR lesions produced by avirulent Pseudomonas spp. in transgenic plants. Pro accumulation was faster and stronger when stimulated by avrRpm1 than by avrRpt2, and was compromised in the low-salicylic acid plants NahG and eds5 when signaled through the RPS2-dependent pathway. In addition, Pro content and AtP5CS2 expression were enhanced by ROS in wild-type plants, suggesting that ROS may function as an intermediate signal in AtP5CS2-mediated Pro accumulation.


2005 ◽  
Vol 14 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Helga Schinkel ◽  
Andreas Schiermeyer ◽  
Raphael Soeur ◽  
Rainer Fischer ◽  
Stefan Schillberg

Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.


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