Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Aug 3;43(8):207.
doi: 10.1007/s00299-024-03289-6.

Cytokinin oxidase2-deficient mutants improve panicle and grain architecture through cytokinin accumulation and enhance drought tolerance in indica rice

Afreen Rashid  1   2 , V Mohan M Achary  3 , M Z Abdin  2 , Sangeetha Karippadakam  1 , Hemangini Parmar  1 , Varakumar Panditi  1 , Ganesan Prakash  4 , Pooja Bhatnagar-Mathur  5 , Malireddy K Reddy  1
Affiliations

Cytokinin oxidase2-deficient mutants improve panicle and grain architecture through cytokinin accumulation and enhance drought tolerance in indica rice

Afreen Rashid et al. Plant Cell Rep. .

Abstract

The Osckx2 mutant accumulates cytokinin thereby enhancing panicle branching, grain yield, and drought tolerance, marked by improved survival rate, membrane integrity, and photosynthetic function. Cytokinins (CKs) are multifaceted hormones that regulate growth, development, and stress responses in plants. Cytokinins have been implicated in improved panicle architecture and grain yield; however, they are inactivated by the enzyme cytokinin oxidase (CKX). In this study, we developed a cytokinin oxidase 2 (Osckx2)-deficient mutant using CRISPR/Cas9 gene editing in indica rice and assessed its function under water-deficit and salinity conditions. Loss of OsCKX2 function increased grain number, secondary panicle branching, and overall grain yield through improved cytokinin content in the panicle tissue. Under drought conditions, the Osckx2 mutant conserved more water and demonstrated improved water-saving traits. Through reduced transpiration, Osckx2 mutants showed an improved survival response than the wild type to unset dehydration stress. Further, Osckx2 maintained chloroplast and membrane integrity and showed significantly improved photosynthetic function under drought conditions through enhanced antioxidant protection systems. The OsCKX2 function negatively affects panicle grain number and drought tolerance, with no discernible impact in response to salinity. The finding suggests the utility of the beneficial Osckx2 allele in breeding to develop climate-resilient, high-yielding cultivars for future food security.

Keywords: ckx2; CRISPR/Cas9; Cytokinin; Drought tolerance; Grain yield; Rice.

PubMed Disclaimer

References

    1. Achary VMM, Patnaik AR, Panda BB (2012) Oxidative biomarkers in leaf tissue of barley seedlings in response to aluminum stress. Ecotoxicol Environ Saf 75:16–26. https://doi.org/10.1016/j.ecoenv.2011.08.015 - DOI
    1. Achary VMM, Reddy MK (2021) CRISPR-Cas9 mediated mutation in GRAIN WIDTH and WEIGHT2 (GW2) locus improves aleurone layer and grain nutritional quality in rice. Sci Rep 11:21941. https://doi.org/10.1038/s41598-021-00828-z - DOI - PubMed - PMC
    1. Akhtar SS, Mekureyaw MF, Pandey C et al (2020) Role of Cytokinins for Interactions of Plants With Microbial Pathogens and Pest Insects. Front Plant Sci 10:1777. https://doi.org/10.3389/fpls.2019.01777 - DOI - PubMed - PMC
    1. Ashikari M, Sakakibara H, Lin S, et al (2005) Cytokinin oxidase regulates rice grain production. Science. 309, 741–745. https://www.science.org/doi/ https://doi.org/10.1126/science.1113373
    1. Ashrafuzzaman M, Islam MR, Ismail MR et al (2009) Evaluation of six aromatic rice varieties for yield and yield contributing characters. Int J Agric Biol 11:616–620

MeSH terms

LinkOut - more resources