Open AccessEctopic phytocystatin expression leads to enhanced drought stress tolerance in soybean ( G lycine max ) and A rabidopsis thaliana through effects on strigolactone pathways and can also result in improved seed traits
Author(s) -
Quain Marian D.,
Makgopa Matome E.,
MárquezGarcía Belén,
Comadira Gloria,
FernandezGarcia Nieves,
Olmos Enrique,
Schnaubelt Daniel,
Kunert Karl J.,
Foyer Christine H.
Publication year - 2014
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12193
Subject(s) - biology , strigolactone , cysteine protease , proteases , ectopic expression , arabidopsis thaliana , cystatin , shoot , microbiology and biotechnology , mutant , drought tolerance , botany , biochemistry , arabidopsis , enzyme , cystatin c , gene , renal function
Summary Ectopic cystatin expression has long been used in plant pest management, but the cysteine protease, targets of these inhibitors, might also have important functions in the control of plant lifespan and stress tolerance that remain poorly characterized. We therefore characterized the effects of expression of the rice cystatin, oryzacystatin‐I (OCI), on the growth, development and stress tolerance of crop (soybean) and model ( A rabidopsis thaliana ) plants. Ectopic OCI expression in soybean enhanced shoot branching and leaf chlorophyll accumulation at later stages of vegetative development and enhanced seed protein contents and decreased the abundance of mRNA s encoding strigolactone synthesis enzymes. The OCI‐expressing A . thaliana showed a slow‐growth phenotype, with increased leaf numbers and enhanced shoot branching at flowering. The OCI‐dependent inhibition of cysteine proteases enhanced drought tolerance in soybean and A . thaliana , photosynthetic CO 2 assimilation being much less sensitive to drought‐induced inhibition in the OCI‐expressing soybean lines. Ectopic OCI expression or treatment with the cysteine protease inhibitor E64 increased lateral root densities in A . thaliana . E64 treatment also increased lateral root densities in the max2‐1 mutants that are defective in strigolactone signalling, but not in the max3‐9 mutants that are defective in strigolactone synthesis. Taken together, these data provide evidence that OCI‐inhibited cysteine proteases participate in the control of growth and stress tolerance through effects on strigolactones. We conclude that cysteine proteases are important targets for manipulation of plant growth, development and stress tolerance, and also seed quality traits.