The Brown Midrib Leaf (bml) Mutation in Rice (Oryza sativa L.) Causes Premature Leaf Senescence and the Induction of Defense Responses

Abstract BackgroundHeat stress is a major environmental factor that could induce premature leaf senescence in plants. So far, few rice premature senescent leaf mutants have been reported to involve in heat tolerance.FindingsWe identified a premature senescence leaf 50 (psl50) mutant that exhibited a higher heat susceptibility with decreased survival rate, over-accumulated hydrogen peroxide (H2O2) content and increased cell death under heat stress compared with the wild-type. The causal gene PREMATURE SENESCENCE LEAF 50 (PSL50) was isolated by using initial map-based resequencing (IMBR) approach, and we found that PSL50 promoted heat tolerance probably by acting as a modulator of H2O2 signaling in response to heat stress in rice (Oryza sativa L.).ConclusionsPSL50 negatively regulates heat-induced premature leaf senescence in rice.

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PREMATURE SENESCENCE LEAF 50 Promotes Heat Stress Tolerance in Rice (Oryza sativa L.)

Rice ◽

10.1186/s12284-021-00493-w ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Yan He ◽

Xiaobo Zhang ◽

Yongfeng Shi ◽

Xia Xu ◽

Liangjian Li ◽

...

Keyword(s):

Oryza Sativa ◽

Heat Stress ◽

Leaf Senescence ◽

Heat Tolerance ◽

Oryza Sativa L ◽

Premature Senescence ◽

Senescent Leaf ◽

Heat Stress Tolerance ◽

Premature Leaf Senescence ◽

Leaf Mutants

Abstract Background Heat stress is a major environmental factor that could induce premature leaf senescence in plants. So far, a few rice premature senescent leaf mutants have been reported to involve in heat tolerance. Findings We identified a premature senescence leaf 50 (psl50) mutant that exhibited a higher heat susceptibility with decreased survival rate, over-accumulated hydrogen peroxide (H2O2) content and increased cell death under heat stress compared with the wild-type. The causal gene PREMATURE SENESCENCE LEAF 50 (PSL50) was isolated by using initial map-based resequencing (IMBR) approach, and we found that PSL50 promoted heat tolerance probably by acting as a modulator of H2O2 signaling in response to heat stress in rice (Oryza sativa L.). Conclusions PSL50 negatively regulates heat-induced premature leaf senescence in rice.

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Isolation and Characterization of Root-Associated Bacterial Endophytes and Their Biocontrol Potential against Major Fungal Phytopathogens of Rice (Oryza sativa L.)

Pathogens ◽

10.3390/pathogens9030172 ◽

2020 ◽

Vol 9 (3) ◽

pp. 172

Author(s):

Maqsood Ahmed Khaskheli ◽

Lijuan Wu ◽

Guoqing Chen ◽

Long Chen ◽

Sajid Hussain ◽

...

Keyword(s):

Oryza Sativa ◽

Fungal Pathogens ◽

Oryza Sativa L ◽

Defense Responses ◽

Growth And Yield ◽

Bacterial Endophytes ◽

16S Rrna Sequence ◽

Resistance Response ◽

Isolation And Characterization ◽

Fungal Phytopathogens

Rice (Oryza sativa L.) is a major cereal food crop worldwide, and its growth and yield are affected by several fungal phytopathogens, including Magnaporthe oryzae, Fusarium graminearum, F. moniliforme, and Rhizoctonia solani. In the present study, we have isolated and characterized root-associated bacterial endophytes that have antifungal activities against rice fungal phytopathogens. A total of 122 root-associated bacterial endophytes, belonging to six genera (Bacillus, Fictibacillus, Lysinibacillus, Paenibacillus, Cupriavidus, and Microbacterium) and 22 species were isolated from three rice cultivars. Furthermore, the 16S rRNA sequence-based phylogeny results revealed that Bacillus was the most dominant bacterial genera, and that there were 15 different species among the isolates. Moreover, 71 root-associated endophytes showed antagonistic effects against four major fungal phytopathogens, including M. oryzae, F. graminearum, F. moniliforme, and R. solani. Additionally, the biochemical, physiological, and PCR amplification results of the antibiotic-related genes further supported the endophytes as potential biocontrolling agents against the rice fungal pathogens. Consequently, the findings in this study suggested that the isolated bacterial endophytes might have beneficial roles in rice defense responses, including several bioactive compound syntheses. The outcomes of this study advocate the use of natural endophytes as an alternative strategy towards the rice resistance response.

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