Short Communications : JIP Analysis on Rice (Oryza sativa cv Nipponbare) Grown under Limited Nitrogen Conditions

( Mark Christian Felipe Reveche Redillas ),( Jin Seo Jeong ),( Reto Jorg Strasser ),( Youn Shic Kim ),( Ju Kon Kim ) 한국응용생명화학회(구 한국농화학회) 2011 Applied Biological Chemistry (Appl Biol Chem) Vol.54 No.5

Nitrogen deficiency significantly reduces the CO2 assimilation capacity of plants and the quantum yield of photosynthesis. Here, we employed the JIP test to determine the effects of nitrogendeficiency on the plant`s photosysnthetic ability on the basis of chlorophyll fluorescence. Nitrogendeficient and nitrogen-replete rice plants were analyzed for the fluorescence transients of the plant leaves in comparison with the nitrogen-sufficient controls. Results showed that 7 day-replete plants behaved normally while 5, 3, and 1 day-replete plants were significantly affected from nitrogen starvation. More specifically, nitrogen starvation of plants resulted in an inactivation of photosystem II (PS II) reaction centers and a decline in electron transport beyond the reduced plastoquinone (QA­), and a decrease in both the pool size and the reduction of end electron acceptors at the PS I. The affected plants were fully recovered from the deficiency after 7 days of nitrogen repletion, as evidenced by the similar level of fluorescence transients to the positive controls. Thus, our results demonstrated that the movement of electron carriers leading to the reduction of end electron acceptors was affected by nitrogen limitation leading to a more pronounced decrease in the reduction of end electron acceptors. Together with the fact that nitrogen-deficiency limits the CO2 assimilation of plants, this study indicates that nitrogen metabolism is tightly coupled with photosynthetic ability.

JIP Analysis on Rice (Oryza sativa cv Nipponbare) Grown under Limited Nitrogen Conditions

Mark Christian Felipe Reveche Redillas,정진서,김주곤 한국응용생명화학회 2011 Applied Biological Chemistry (Appl Biol Chem) Vol.54 No.5

Nitrogen deficiency significantly reduces the CO2 assimilation capacity of plants and the quantum yield of photosynthesis. Here, we employed the JIP test to determine the effects of nitrogendeficiency on the plant's photosysnthetic ability on the basis of chlorophyll fluorescence. Nitrogendeficient and nitrogen-replete rice plants were analyzed for the fluorescence transients of the plant leaves in comparison with the nitrogen-sufficient controls. Results showed that 7 day-replete plants behaved normally while 5, 3, and 1 day-replete plants were significantly affected from nitrogen starvation. More specifically, nitrogen starvation of plants resulted in an inactivation of photosystem II (PS II) reaction centers and a decline in electron transport beyond the reduced plastoquinone (QA −), and a decrease in both the pool size and the reduction of end electron acceptors at the PS I. The affected plants were fully recovered from the deficiency after 7 days of nitrogen repletion, as evidenced by the similar level of fluorescence transients to the positive controls. Thus, our results demonstrated that the movement of electron carriers leading to the reduction of end electron acceptors was affected by nitrogen limitation leading to a more pronounced decrease in the reduction of end electron acceptors. Together with the fact that nitrogen-deficiency limits the CO2 assimilation of plants, this study indicates that nitrogen metabolism is tightly coupled with photosynthetic ability.

JIP Analysis on Rice (Oryza sativa cv Nipponbare) Grown under Limited Nitrogen Conditions

Redillas, Mark Christian Felipe Reveche,Jeong, Jin-Seo,Strasser, Reto Jorg,Kim, Youn-Shic,Kim, Ju-Kon The Korean Society for Applied Biological Chemistr 2011 Applied Biological Chemistry (Appl Biol Chem) Vol.54 No.5

Nitrogen deficiency significantly reduces the $CO_2$ assimilation capacity of plants and the quantum yield of photosynthesis. Here, we employed the JIP test to determine the effects of nitrogen-deficiency on the plant's photosysnthetic ability on the basis of chlorophyll fluorescence. Nitrogen-deficient and nitrogen-replete rice plants were analyzed for the fluorescence transients of the plant leaves in comparison with the nitrogen-sufficient controls. Results showed that 7 day-replete plants behaved normally while 5, 3, and 1 day-replete plants were significantly affected from nitrogen starvation. More specifically, nitrogen starvation of plants resulted in an inactivation of photosystem II (PS II) reaction centers and a decline in electron transport beyond the reduced plastoquinone ($Q_A^-$), and a decrease in both the pool size and the reduction of end electron acceptors at the PS I. The affected plants were fully recovered from the deficiency after 7 days of nitrogen repletion, as evidenced by the similar level of fluorescence transients to the positive controls. Thus, our results demonstrated that the movement of electron carriers leading to the reduction of end electron acceptors was affected by nitrogen limitation leading to a more pronounced decrease in the reduction of end electron acceptors. Together with the fact that nitrogen-deficiency limits the $CO_2$ assimilation of plants, this study indicates that nitrogen metabolism is tightly coupled with photosynthetic ability.

Overexpression of <i>OsERF48</i> causes regulation of <i>OsCML16</i> , a calmodulin‐like protein gene that enhances root growth and drought tolerance

Jung, Harin,Chung, Pil Joong,Park, Su‐,Hyun,Redillas, Mark Christian Felipe Reveche,Kim, Youn Shic,Suh, Joo‐,Won,Kim, Ju‐,Kon BLACKWELL 2017 PLANT BIOTECHNOLOGY JOURNAL Vol.15 No.10

<P><B>Summary</B></P><P>The AP2/ERF family is a plant‐specific transcription factor family whose members have been associated with various developmental processes and stress tolerance. Here, we functionally characterized the drought‐inducible <I>OsERF48</I>, a group Ib member of the rice ERF family with four conserved motifs, CMI‐1, ‐2, ‐3 and ‐4. A transactivation assay in yeast revealed that the C‐terminal CMI‐1 motif was essential for OsERF48 transcriptional activity. When <I>OsERF48</I> was overexpressed in an either a root‐specific (ROXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP>) or whole‐body (OXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP>) manner, transgenic plants showed a longer and denser root phenotype compared to the nontransgenic (NT) controls. When plants were grown on a 40% polyethylene glycol‐infused medium under <I>in vitro</I> drought conditions, ROXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP> plants showed a more vigorous root growth than OXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP> and NT plants. In addition, the ROXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP> plants exhibited higher grain yield than OXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP> and NT plants under field‐drought conditions. We constructed a putative <I>OsERF48</I> regulatory network by cross‐referencing ROXO<SUP><I>s</I></SUP>ERF<SUP><I>48</I></SUP> root‐specific RNA‐seq data with a co‐expression network database, from which we inferred the involvement of 20 drought‐related genes in <I>OsERF48</I>‐mediated responses. These included genes annotated as being involved in stress signalling, carbohydrate metabolism, cell‐wall proteins and drought responses. They included, <I>OsCML16</I>, a key gene in calcium signalling during abiotic stress, which was shown to be a direct target of OsERF48 by chromatin immunoprecipitation‐qPCR analysis and a transient protoplast expression assay. Our results demonstrated that OsERF48 regulates <I>OsCML16</I>, a calmodulin‐like protein gene that enhances root growth and drought tolerance.</P>

Analysis of the APX, PGD1 and R1G1B constitutive gene promoters in various organs over three homozygous generations of transgenic rice plants.

Park, Su-Hyun,Bang, Seung Woon,Jeong, Jin Seo,Jung, Harin,Redillas, Mark Christian Felipe Reveche,Kim, Hyung Il,Lee, Kang Hyun,Kim, Youn Shic,Kim, Ju-Kon Springer-Verlag [etc.] 2012 Planta Vol.235 No.6

<P>We have previously characterized the constitutively active promoters of the APX, PGD1 and R1G1B genes in rice (Park et al. 2010 in J Exp Bot 61:2459-2467). To have potential crop biotechnology applications, gene promoters must be stably active over many generations. In our current study, we report our further detailed analysis of the APX, PGD1 and R1G1B gene promoters in various organs and tissues of transgenic rice plants for three (T?????????) homozygous generations. The copy numbers in 37 transgenic lines that harbor promoter:gfp constructs were determined and promoter activities were measured by real-time qPCR. Analysis of the 37 lines revealed that 15 contained a single copy of one of the three promoter:gfp chimeric constructs. The promoter activity levels were generally higher in multi-copy lines, whereas variations in these levels over the T????????? generations studied were observed to be smaller in single-copy than in multi-copy lines. The three promoters were further found to be highly active in the whole plant body at both the vegetative and reproductive stages of plant growth, with the exception of the APX in the ovary and R1G1B in the pistil and filaments where zero or very low levels of activity were detected. Of note, the spatial activities of the PGD1 promoter were found to be strikingly similar to those of the ZmUbi1, a widely used constitutive promoter. Our comparison of promoter activities between T???, T??? and T??? plants revealed that the APX, PGD1 and R1G1B promoters maintained their activities at comparable levels in leaves and roots over three homozygous generations and are therefore potentially viable alternative promoters for crop biotechnology applications.</P>