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Knockdown of an inflorescence meristem‐specific cytokinin oxidase – OsCKX2 in rice reduces yield penalty under salinity stress condition
Author(s) -
Joshi Rohit,
Sahoo Khirod Kumar,
Tripathi Amit Kumar,
Kumar Ritesh,
Gupta Brijesh Kumar,
Pareek Ashwani,
SinglaPareek Sneh Lata
Publication year - 2018
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12947
Subject(s) - cytokinin , meristem , inflorescence , salinity , panicle , biology , abiotic stress , gene knockdown , abiotic component , horticulture , botany , auxin , agronomy , shoot , biochemistry , gene , ecology , paleontology
Abstract Cytokinins play a significant role in determining grain yield in plants. Cytokinin oxidases catalyse irreversible degradation of cytokinins and hence modulate cellular cytokinin levels. Here, we studied the role of an inflorescence meristem‐specific rice cytokinin oxidase – OsCKX2 – in reducing yield penalty under salinity stress conditions. We utilized an RNAi‐based approach to study the function of OsCKX2 in maintaining grain yield under salinity stress condition. Ultra‐performance liquid chromatography‐based estimation revealed a significant increase in cytokinins in the inflorescence meristem of OsCKX2 ‐knockdown plants. To determine if there exists a correlation between OsCKX2 levels and yield under salinity stress condition, we assessed the growth, physiology and grain yield of OsCKX2‐knockdown plants vis‐à‐vis the wild type. OsCKX2‐knockdown plants showed better vegetative growth, higher relative water content and photosynthetic efficiency and reduced electrolyte leakage as compared with the wild type under salinity stress. Importantly, we found a negative correlation between OsCKX2 expression and plant productivity as evident by assessment of agronomical parameters such as panicle branching, filled grains per plant and harvest index both under control and salinity stress conditions. These results suggest that OsCKX2 , via controlling cytokinin levels, regulates floral primordial activity modulating rice grain yield under normal as well as abiotic stress conditions.