Molecular, anatomical and  physiological properties of a genetically modified soybean line transformed  with rd29A:AtDREB1A for the improvement of drought tolerance.
We  evaluated the molecular, anatomical and physiological properties of a soybean  line transformed to improve drought tolerance with an rd29A:AtDREB1A construct.  This construct expressed dehydration- responsive element binding protein DREB1A  from the stress-inducible rd29A promoter. The greenhouse growth test  included four randomized blocks of soybean plants, with each treatment  performed in triplicate. Seeds from the non-transformed soybean cultivar BR16  and from the genetically modified soybean P58 line (T(2) generation)  were grown at 15% gravimetric humidity for 31 days. To induce water deficit,  the humidity was reduced to 5% gravimetric humidity (moderate stress) for 29 days  and then to 2.5% gravimetric humidity (severe stress). AtDREB1A gene  expression was higher in the genetically modified P58 plants during water  deficit, demonstrating transgene stability in T(2) generations  and induction of the rd29A promoter. Drought-response genes, including GmPI-PLC, GmSTP, GmGRP, and GmLEA14, were highly expressed in plants  submitted to severe stress. Genetically modified plants had higher stomatal  conductance and consequently higher photosynthetic and transpiration rates. In  addition, they had more chlorophyll. Overexpression of AtDREB1A may  contribute to a decrease in leaf thickness; however, a thicker abaxial  epidermis was observed. Overexpression of AtDREB1A in soybean appears to  enhance drought tolerance.
Departamento de Genética, Universidade Estadual de Londrina, Londrina, PR, Brasil.
A M
AM
Polizel
M E
ME
Medri
K
K
Nakashima
N
N
Yamanaka
J R B
JR
Farias
M C N
MC
de Oliveira
S R R
SR
Marin
R V
RV
Abdelnoor
F C
FC
Marcelino-Guimarães
R
R
Fuganti
F A
FA
Rodrigues
R
R
Stolf-Moreira
M A
MA
Beneventi
A A P
AA
Rolla
N
N
Neumaier
K
K
Yamaguchi-Shinozaki
J F C
JF
Carvalho
A L
AL
Nepomuceno
D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D058503:Mesophyll Cells / Q000166:cytology / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013025:Glycine max / Q000033:anatomy & histology* / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
D029681:Arabidopsis Proteins; C114578:DREB1A protein, Arabidopsis; C520629:RD29a protein, Arabidopsis; D014157:Transcription Factors