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Nitric oxide is essential for the development of aerenchyma in wheat roots under hypoxic stress
Author(s) -
Wany Aakanksha,
Kumari Aprajita,
Gupta Kapuganti Jagadis
Publication year - 2017
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.13061
Subject(s) - aerenchyma , biology , nitric oxide , microbiology and biotechnology , biochemistry , nitric oxide synthase , botany , enzyme , endocrinology
Abstract In response to flooding/waterlogging, plants develop various anatomical changes including the formation of lysigenous aerenchyma for the delivery of oxygen to roots. Under hypoxia, plants produce high levels of nitric oxide (NO) but the role of this molecule in plant‐adaptive response to hypoxia is not known. Here, we investigated whether ethylene‐induced aerenchyma requires hypoxia‐induced NO. Under hypoxic conditions, wheat roots produced NO apparently via nitrate reductase and scavenging of NO led to a marked reduction in aerenchyma formation. Interestingly, we found that hypoxically induced NO is important for induction of the ethylene biosynthetic genes encoding ACC synthase and ACC oxidase. Hypoxia‐induced NO accelerated production of reactive oxygen species, lipid peroxidation, and protein tyrosine nitration. Other events related to cell death such as increased conductivity, increased cellulase activity, DNA fragmentation, and cytoplasmic streaming occurred under hypoxia, and opposing effects were observed by scavenging NO. The NO scavenger cPTIO (2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide potassium salt) and ethylene biosynthetic inhibitor CoCl 2 both led to reduced induction of genes involved in signal transduction such as phospholipase C, G protein alpha subunit, calcium‐dependent protein kinase family genes CDPK , CDPK2 , CDPK 4 , Ca‐CAMK , inositol 1,4,5‐trisphosphate 5‐phosphatase 1 , and protein kinase suggesting that hypoxically induced NO is essential for the development of aerenchyma.