ABSTRACT
A previously identified wheat drought stress responsive Universal stress protein, TaUSP_3B-1 has been found to work in an auxin dependent manner in the plant root tissues in the differentiation zone. We also found a novel interacting partner, TaGolS, which physically interacts with TaUSP_3B-1 and colocalizes in the endoplasmic reticulum. TaGolS is a key enzyme in the RFO (Raffinose oligosaccharides) biosynthesis which is well reported to provide tolerance under water deficit conditions. TaUSP_3B-1 overexpression lines showed an early flowering phenotype under drought stress which might be attributed to the increased levels of AtTPPB and AtTPS transcripts under drought stress. Moreover, at the cellular levels ER stress induced TaUSP_3B-1 transcription and provides tolerance in both adaptive and acute ER stress via less ROS accumulation in the overexpression lines. TaUSP_3B-1 overexpression plants had increased silique numbers and a denser root architecture as compared to the WT plants under drought stress.
Subject(s)
Droughts , Endoplasmic Reticulum Stress , Gene Expression Regulation, Plant , Indoleacetic Acids , Plant Proteins , Indoleacetic Acids/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Endoplasmic Reticulum Stress/physiology , Stress, Physiological/genetics , Triticum/genetics , Triticum/physiology , Triticum/metabolism , Plant Roots/metabolism , Plant Roots/genetics , Plant Roots/physiology , Plants, Genetically Modified , Reactive Oxygen Species/metabolism , Endoplasmic Reticulum/metabolismABSTRACT
KEY MESSAGE: TaUSPs are localized in Endoplasmic reticulum and form homo and hetero dimers within themselves. They play significant role in multiple abiotic stress responses in yeast heterologous system and in plants. Universal Stress Proteins are stress responsive proteins present in a variety of life forms ranging from bacteria to multicellular plants and animals. In this study we have identified 85 TaUSP genes in the wheat genome and have characterised their abiotic stress responsive members in yeast under different stress conditions. Localization and Y2H studies suggest that wheat, USP proteins are localized in the ER complex, and extensively crosstalk amongst themselves through forming hetero and homodimers. Expression analysis of these TaUSP genes suggests their role in adaptation to multiple abiotic stresses. TaUSP_5D-1 was found to have some DNA binding activity in yeast. Certain abiotic stress responsive TaUSP genes are found to impart tolerance to temperature stress, oxidative stress, ER stress (DTT treatment) and LiCl2 stress in the yeast heterologous system. TaUSP_5D-1 overexpression in A. thaliana imparts drought tolerance via better lateral root network in transgenic lines. The TaUSP represents an important repertoire of genes for engineering abiotic stress responsiveness in crop plants.
