<p>In a world-first, Japanese scientists have used the CRISPR gene-editing tool to change the colour of ornamental morning glory flowers from violet to white by tweaking a single gene.<br /><br />Japanese morning glory, or Asagao, was chosen for this study as it is one of two traditional horticultural model plants in the National BioResource Project in Japan (NBRP).<br /><br />Extensive genetic studies of this plant have already been performed, its genome sequenced and DNA transfer methods established.<br /><br />As public concern with genetic technologies such as CRISPR/Cas9 is currently a social issue in Japan, studies using this popular and widely-grown plant may help to educate the public on this topic, researchers said.<br /><br />Researchers from the University of Tsukuba, the National Agriculture and Food Research Organization (NARO) and Yokohama City University in Japan targeted a single gene DFR-B, encoding an enzyme responsible for the colour of the plant's stems, leaves and flowers.<br /><br />Two other very closely related genes (DFR-A and DRF-C) sit side-by-side, next to DFR-B. Therefore, the challenge was to specifically and accurately target the DFR-B gene without altering the other genes. The CRISPR/Cas9 system was used as it is currently the most precise method of gene editing.<br /><br />The CRISPR/Cas9 system is based on a bacterial defense mechanism.<br />It is composed of two molecules that alter the DNA sequence. Cas9, an enzyme, cuts the two strands of DNA in a precise location so that DNA can be added or removed.<br /><br />Cas9 is guided to the correct location by gRNA, or guide RNA, a small piece of RNA that has been designed to be complementary to the target DNA sequence.<br />Cas9 cuts the two strands of DNA at the target location, allowing DNA to be removed and/or added.<br /><br />This technology is also extremely useful in confirming the function of genes.<br />The CRISPR/Cas9 system can be used to find out what an organism looks like after a known gene is disrupted, and confirms that the DFR-B gene is the main gene responsible for colour in Japanese morning glory plants.<br /><br />Currently, CRISPR/Cas9 technology is not 100 per cent efficient, that is, not all targeted plants will be transgenic.<br /><br />The mutation rate in the current study was 75 per cent, which is relatively high.<br />This is one of the reasons this research will greatly facilitate those interested in the modification of flower colours and shapes using the CRISPR/Cas9 system in ornamental flowers or vegetables.<br /><br />The story of the Japanese morning glory started in the 8th century AD, with the introduction of wild blue-flowered plants into Japan from China.<br /><br />In 1631, the first white-flowered Japanese morning glory was painted in Japan. What took nature nearly 850 years to achieve has taken less than one using the CRISPR/Cas9 system, indicating both its power and its potential.</p>
<p>In a world-first, Japanese scientists have used the CRISPR gene-editing tool to change the colour of ornamental morning glory flowers from violet to white by tweaking a single gene.<br /><br />Japanese morning glory, or Asagao, was chosen for this study as it is one of two traditional horticultural model plants in the National BioResource Project in Japan (NBRP).<br /><br />Extensive genetic studies of this plant have already been performed, its genome sequenced and DNA transfer methods established.<br /><br />As public concern with genetic technologies such as CRISPR/Cas9 is currently a social issue in Japan, studies using this popular and widely-grown plant may help to educate the public on this topic, researchers said.<br /><br />Researchers from the University of Tsukuba, the National Agriculture and Food Research Organization (NARO) and Yokohama City University in Japan targeted a single gene DFR-B, encoding an enzyme responsible for the colour of the plant's stems, leaves and flowers.<br /><br />Two other very closely related genes (DFR-A and DRF-C) sit side-by-side, next to DFR-B. Therefore, the challenge was to specifically and accurately target the DFR-B gene without altering the other genes. The CRISPR/Cas9 system was used as it is currently the most precise method of gene editing.<br /><br />The CRISPR/Cas9 system is based on a bacterial defense mechanism.<br />It is composed of two molecules that alter the DNA sequence. Cas9, an enzyme, cuts the two strands of DNA in a precise location so that DNA can be added or removed.<br /><br />Cas9 is guided to the correct location by gRNA, or guide RNA, a small piece of RNA that has been designed to be complementary to the target DNA sequence.<br />Cas9 cuts the two strands of DNA at the target location, allowing DNA to be removed and/or added.<br /><br />This technology is also extremely useful in confirming the function of genes.<br />The CRISPR/Cas9 system can be used to find out what an organism looks like after a known gene is disrupted, and confirms that the DFR-B gene is the main gene responsible for colour in Japanese morning glory plants.<br /><br />Currently, CRISPR/Cas9 technology is not 100 per cent efficient, that is, not all targeted plants will be transgenic.<br /><br />The mutation rate in the current study was 75 per cent, which is relatively high.<br />This is one of the reasons this research will greatly facilitate those interested in the modification of flower colours and shapes using the CRISPR/Cas9 system in ornamental flowers or vegetables.<br /><br />The story of the Japanese morning glory started in the 8th century AD, with the introduction of wild blue-flowered plants into Japan from China.<br /><br />In 1631, the first white-flowered Japanese morning glory was painted in Japan. What took nature nearly 850 years to achieve has taken less than one using the CRISPR/Cas9 system, indicating both its power and its potential.</p>