BULLETIN 1
Experts Use Genome Editing to Make Tomatoes Yield Earlier

 

 Figure: Tomato plant with an unfavorable natural mutation (on the left) and a tomato plant in with the mutation was repaired by genome editing (on the right). The repair of the mutation leads to earlier fruit yield. (Scale: 7.5 cm) Photo by Anna Glaus, UNIL
Researchers in the laboratory of Sebastian Soyk at the Swiss University of Lausanne (UNIL) used genome editing technology, called base editing, to change one of the ~850 million DNA base pairs in the tomato gene to repair an unfavorable domestication mutation.
The researchers used based editing to repair an existing mutation in tomato, the world's second most consumed vegetable crop. Doctoral student Anna Glaus first selected and then investigated the mutated and repaired plants. Glaus characterized 72 plants and harvested during two consecutive days 4,500 fruits that were sorted by size, weight, and maturity (red or green). The sugar content was also measured.
By repairing the deleterious domestication mutation with genome editing, the researchers have obtained a tomato variety that is earlier yielding. Considering, the Swiss moratorium banning the growth of genetically modified organism (GMO), which expires in June 2025, this new study is thought-provoking. “We show here the varied application of genome editing and its benefit for agriculture”, says Anna Glaus.
For more details, read the news release from UNIL (in French).
See https://www.isaaa.org/kc/cropbiotechupdate/ged/article/default.asp?ID=21158

BULLETIN 2
Researchers Identify Gene Controlling Growth and Development in Bananas

A study published in Molecular Breeding shows that MaGA20ox2f regulates flowering time and fruit yield in bananas. MaGA20ox2f is the closest homolog to the SD1, a gene that is known to increase yield in rice, in the banana genome.
Previous studies found that two banana GA20 oxidase2 (MaGA20ox2) genes, Ma04g15900 and Ma08g32850, have vital roles in controlling the growth and development of bananas. However, the biological function of each gene has not been understood and studied. As such, the researchers used CRISPR-Cas9 technology to knock out MaGA20ox2f and examine its effects on bananas.
The study showed that the knockout of MaGA20ox2f resulted in delayed flowering by 58 to 61 days and reduced fruit yield by 81.13% and 76.23% compared to the wild-type counterparts under normal conditions. The researchers hypothesized that reduced chlorophyll contents in the leaves and GA1 deficiency in the fruits are key factors behind their delayed flowering and low yields.
For more information, read the abstract from Molecular Breeding.
See https://www.isaaa.org/kc/cropbiotechupdate/ged/article/default.asp?ID=21159

SCIENTIFIC NEWS
OsNCED5 confers cold stress tolerance through regulating ROS homeostasis in rice
Zhipan Xiang, Lin Zhang, Mingze Zhang, Yuxian Yao, Qianqian Qian, Ziyi Wei, Baolu Cui, Dengyan Wang, Changbin Quan, Minfeng Lu, Liangbi Chen
Plant Physioloy and Biochemistry; Volume 220, March 2025, 109455

  

Abstract
Cold stress is one of the most serious abiotic stresses that affects the growth and yield in rice. However, the molecular mechanism by which abscisic acid (ABA) regulates plant cold stress tolerance is not yet clear. In this study, we identified a member of the OsNCED (9-cis-epoxycarotenoid dioxygenase) gene family, OsNCED5, which confers cold stress tolerance in rice. OsNCED5 encodes a chloroplast-localized ABA biosynthetic enzyme and its expression is strongly induced by cold stress. Disruption of OsNCED5 by CRISPR/Cas9-mediated mutagenesis led to a significant decrease in ABA content and exhibited significant reduced cold stress tolerance at the seedling stage. Exogenous ABA restored the cold stress tolerance of the osnced5 mutants. Overexpression of OsNCED5 gene significantly improved the cold stress tolerance of rice seedlings. Moreover, OsNCED5 mainly regulates cold stress tolerance through regulating reactive oxygen species (ROS) homeostasis. Taken together, we identified a new OsNCED regulator involved in cold stress tolerance, and provided a potential target gene for enhancing cold stress tolerance in rice.
See https://www.sciencedirect.com/science/article/abs/pii/S0981942824011239