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Systemic regulation of sulfur homeostasis in Medicago truncatula
- Source :
- Planta. 239:79-96
- Publication Year :
- 2013
- Publisher :
- Springer Science and Business Media LLC, 2013.
-
Abstract
- Sulfur (S) is an essential macronutrient for plants, and deficiency in soil S availability limits plant growth. Adaptive strategies have been evolved by plants to respond to S deficiency by coordinating systemic regulatory mechanism. A split-root experiment using legume model plant Medicago truncatula Gaertn. was conducted to investigate the systemic response to S deficiency. Plant growth, root morphology and S contents under varying conditions of S supply were determined, and the expression of genes encoding sulfate transporter (MtSULTRs) and MtAPR1 encoding an enzyme involved in S assimilation was monitored. Our results demonstrated that there was an apparent systemic response of M. truncatula to heterogeneous S supply in terms of root length, S contents, and S uptake and assimilation at the transcriptional level. When exposed to heterogeneous S supply, M. truncatula plants showed proliferation of lateral roots in S-rich medium and reduction in investment to S-depleted roots. Growth was stimulated with half-part of roots exposed to S-deficient medium. There were different expression patterns of MtSULTRs and MtAPR1 in response to heterogeneous S supply both in roots and shoots of M. truncatula. Expression of MtSULTR1.1 and MtSULTR1.3 was systemically responsive to S deficiency, leading to an enhancement of S uptake in roots exposed to S-sufficient medium. In addition, the response of S-deprived seedlings to re-supply of sulfate and Cys was also analyzed. It was shown that sulfate, but not Cys, may serve as a systemic signal to regulate the expression of genes associated with S absorption and assimilation in M. truncatula. These findings provide a comprehensive picture of systemic responses to S deficiency in leguminous species.
- Subjects :
- Plant Science
Plant Roots
Soil
Gene Expression Regulation, Plant
Medicago truncatula
Botany
Genetics
Homeostasis
Oxidoreductases Acting on Sulfur Group Donors
Cysteine
Gene
Legume
Plant Proteins
chemistry.chemical_classification
Medicago
biology
Sulfates
fungi
food and beverages
Assimilation (biology)
biology.organism_classification
Culture Media
Enzyme
chemistry
Shoot
Carrier Proteins
Plant Shoots
Sulfur
Subjects
Details
- ISSN :
- 14322048 and 00320935
- Volume :
- 239
- Database :
- OpenAIRE
- Journal :
- Planta
- Accession number :
- edsair.doi.dedup.....8ef9c83d858615aef1f9626d319909a7