The complete open reading frame of OsPINla was amplified through reverse transcriptase- polymerase chain reaction （RT-PCR） based on the sequence deposited in GenBank to explore the relationship between the auxin eff...The complete open reading frame of OsPINla was amplified through reverse transcriptase- polymerase chain reaction （RT-PCR） based on the sequence deposited in GenBank to explore the relationship between the auxin efflux protein OsPINla and the negative phototropism of rice roots. Sequencing results showed that the GC content of OsPINla was 65.49%. The fusion expression vector pCAMBIA-1301-OsP/N1a：：GFP containing the OsPINla gene and a coding green fluorescent protein （gfp） gene was constructed. The fusion vector was transferred into onion epidermal cells by Agrobacterium tumefaciens transformation. The transient expression of OsPINla-GFP was mainly located in the nucleus and cell membrane. Moreover, the transgenic plants were obtained by Agrobacterium-mediated genetic transformation. Molecular detection performed by using PCR and β-glucuronidase staining showed that the target construct was integrated into the genome of rice. The negative phototropic curvatures of the transgenic rice roots were higher than those of the wild type. Similarly, the expression levels of OsPINla in the transgenic plants were considerably higher than those in the wild-type plants. These results suggest that OsPINla is crucial in the negative phototropic curvature of rice roots.展开更多
Calcium ions （Ca2＋） act as an intracellular second messenger and affect nearly all aspects of cellular life. They are functioned by interacting with polar auxin transport, and the negative phototropism of plant roo...Calcium ions （Ca2＋） act as an intracellular second messenger and affect nearly all aspects of cellular life. They are functioned by interacting with polar auxin transport, and the negative phototropism of plant roots is caused by the transport of auxin from the irradiated side to the shaded side of the roots. To clarify the role of calcium signaling in the modulation of rice root negative phototropism, as well as the relationship between polar auxin transport and calcium signaling, calcium signaling reagents were used to treat rice seminal roots which were cultivated in hydroculture and unilaterally illuminated at an intensity of 100-200 pmol/（m2.s） for 24 h. Negative phototropism curvature and growth rate of rice roots were both promoted by exogenous CaCI2 lower than 100 pmol/L, but inhibited by calcium channel blockers （verapamil and LaCI3）, calcineurin inhibitor （chlorpromazine, CPZ）, and polar auxin transport inhibitor （N-l-naphthylphthalamic acid, NPA）. Roots stopped growing and negative phototropism disappeared when the concentrations increased to 100 pmol/L verapamil, 12.500 ~Jmol/L LaCI3, 60 pmol/L CPZ, and 6 pmol/L NPA. Moreover, 100 pmol/L CaCI2 could relieve the inhibition of LaCI3, verapamil and NPA. The enhanced negative phototropism curvature was caused by the transportation of more auxin from the irradiated side to the shaded side in the presence of exogenous Ca2＋. Calcium signaling plays a key role as a second messenger in the process of light signal regulation of rice root growth and negative phototropism.展开更多
基金supported by the grants from the National Natural Science Foundations of China(Grant Nos.31071353 and 31100197)the Anhui Provincial Natural Science Fund of Youth,China(Grant No.1308085QC50)the Fund of Provincial Excellent Young Talents in Universities and Colleges,China(Grant No.2012SQRL057)
文摘The complete open reading frame of OsPINla was amplified through reverse transcriptase- polymerase chain reaction （RT-PCR） based on the sequence deposited in GenBank to explore the relationship between the auxin efflux protein OsPINla and the negative phototropism of rice roots. Sequencing results showed that the GC content of OsPINla was 65.49%. The fusion expression vector pCAMBIA-1301-OsP/N1a：：GFP containing the OsPINla gene and a coding green fluorescent protein （gfp） gene was constructed. The fusion vector was transferred into onion epidermal cells by Agrobacterium tumefaciens transformation. The transient expression of OsPINla-GFP was mainly located in the nucleus and cell membrane. Moreover, the transgenic plants were obtained by Agrobacterium-mediated genetic transformation. Molecular detection performed by using PCR and β-glucuronidase staining showed that the target construct was integrated into the genome of rice. The negative phototropic curvatures of the transgenic rice roots were higher than those of the wild type. Similarly, the expression levels of OsPINla in the transgenic plants were considerably higher than those in the wild-type plants. These results suggest that OsPINla is crucial in the negative phototropic curvature of rice roots.
基金supported by the National Natural Science Foundation of China (Grant No. 31071353) the Open Fund of Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization of Huanggang Normal University, China (Grant Nos. 2013000503 and 2011BLKF243)
文摘Calcium ions （Ca2＋） act as an intracellular second messenger and affect nearly all aspects of cellular life. They are functioned by interacting with polar auxin transport, and the negative phototropism of plant roots is caused by the transport of auxin from the irradiated side to the shaded side of the roots. To clarify the role of calcium signaling in the modulation of rice root negative phototropism, as well as the relationship between polar auxin transport and calcium signaling, calcium signaling reagents were used to treat rice seminal roots which were cultivated in hydroculture and unilaterally illuminated at an intensity of 100-200 pmol/（m2.s） for 24 h. Negative phototropism curvature and growth rate of rice roots were both promoted by exogenous CaCI2 lower than 100 pmol/L, but inhibited by calcium channel blockers （verapamil and LaCI3）, calcineurin inhibitor （chlorpromazine, CPZ）, and polar auxin transport inhibitor （N-l-naphthylphthalamic acid, NPA）. Roots stopped growing and negative phototropism disappeared when the concentrations increased to 100 pmol/L verapamil, 12.500 ~Jmol/L LaCI3, 60 pmol/L CPZ, and 6 pmol/L NPA. Moreover, 100 pmol/L CaCI2 could relieve the inhibition of LaCI3, verapamil and NPA. The enhanced negative phototropism curvature was caused by the transportation of more auxin from the irradiated side to the shaded side in the presence of exogenous Ca2＋. Calcium signaling plays a key role as a second messenger in the process of light signal regulation of rice root growth and negative phototropism.
