Cysteine protease and cystatin expression and activity during soybean nodule development and senescence

BMC Plant Biology

Research Article

Christoper Ashley Cullis¹  Stefan George van Wyk²  Barend Juan Vorster²  Magdeleen Du Plessis²  Karl Josef Kunert³ 

[1] Department of Biology, Case Western Reserve University Cleveland, 44106, Cleveland, OH, USA;Department of Plant Production and Soil Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria, 0002, Pretoria, South Africa;Department of Plant Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria, 0002, Pretoria, South Africa;

关键词: Cystatin(s);    Cysteine protease(s);    Programmed cell death;    RNASeq;    Senescence;    Soybean;    Symbiotic nitrogen fixation;    Transcriptome;   

DOI  :  10.1186/s12870-014-0294-3

 received in 2014-06-11, accepted in 2014-10-17,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundNodules play an important role in fixing atmospheric nitrogen for soybean growth. Premature senescence of nodules can negatively impact on nitrogen availability for plant growth and, as such, we need a better understanding of nodule development and senescence. Cysteine proteases are known to play a role in nodule senescence, but knowledge is still fragmented regarding the function their inhibitors (cystatins) during the development and senescence of soybean nodules. This study provides the first data with regard to cystatin expression during nodule development combined with biochemical characterization of their inhibition strength.ResultsSeventy nine non-redundant cysteine protease gene sequences with homology to papain, belonging to different subfamilies, and several legumain-like cysteine proteases (vacuole processing enzymes) were identified from the soybean genome assembly with eighteen of these cysteine proteases actively transcribed during nodule development and senescence. In addition, nineteen non-redundant cystatins similar to oryzacystatin-I and belonging to cystatin subgroups A and C were identified from the soybean genome assembly with seven actively transcribed in nodules. Most cystatins had preferential affinity to cathepsin L-like cysteine proteases. Transcription of cystatins Glyma05g28250, Glyma15g12211, Glyma15g36180 particularly increased during onset of senescence, possibly regulating proteolysis when nodules senesce and undergo programmed cell death. Both actively transcribed and non-actively transcribed nodule cystatins inhibited cathepsin-L- and B-like activities in different age nodules and they also inhibited papain and cathepsin-L activity when expressed and purified from bacterial cells.ConclusionsOverlap in activities and specificities of actively and non-actively transcribed cystatins raises the question if non-transcribed cystatins provide a reservoir for response to particular environments. This data might be applicable to the development of strategies to extend the active life span of nodules or prevent environmentally induced senescence.

【 授权许可】

Unknown   
© van Wyk et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.