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This study investigated the effects of dietary supplementation with anthocyanin extracted from black rice bran (AR) on the growth rate, immunological response, and expression of immune and antioxidant genes in Nile tilapia raised in an indoor biofloc system. A total of 300 Nile tilapia fingerlings (15.14 ± 0.032 g) were maintained in 150 L tanks and acclimatized for two weeks. Five experimental AR diets (0, 1, 2, 4, and 8 g kg−1) with various anthocyanin doses were used to feed the fish. We observed that the growth and feed utilization of fish fed with different dietary AR levels increased significantly after eight weeks (p < 0.05). In addition, the serum immunity of fish fed AR diets was much greater than that of those fed non-AR diets (p < 0.05). However, there were little or no difference in between fish fed AR enriched diets and the control AR-free diet (p > 0.05). After eight weeks, fish fed AR-supplemented diets had significantly higher mRNA transcript levels in immune (interleukin [ IL ] -1 , IL-8 , and liposaccharide-binding protein [ LBP ]) and antioxidant (glutathione transferase-alpha [ GST-α ] and glutathione reductase [ GSR ]) genes compared to control fish fed the AR-free diet, with the greatest enhancement of mRNA transcript levels (in the case of IL- 8 by up to about 5.8-fold) in the 4 g kg−1 AR diet. These findings suggest that dietary inclusion of AR extract from black rice bran at 4–8 g kg−1 could function as a herbal immunostimulant to enhance growth performance, feed consumption, and immunity in Nile tilapia. • Nile tilapia fed anthocyanins extracted from dark rice bran (AR) significantly improved growth performance. • AR supplemented diets enhanced lysozyme activity in blood serum and to a lesser degree in skin mucus. • AR diets significantly increased mRNA transcript rates of IL-1 , IL-8 , LBP , GST-α , GPX , and GSR gene expressions. [ABSTRACT FROM AUTHOR]

Functional studies of CCCH-type zinc finger proteins in abiotic stress responses have largely focused on tandem CCCH-type zinc finger (TZF) genes, whereas the study of functional roles of non-TZF genes in abiotic stress responses has largely been neglected. Here, we investigated the functional roles of AtC3H17 , a non-TZF gene of Arabidopsis, in salt stress responses. AtC3H17 expression significantly increased under NaCl, mannitol, and ABA treatments. AtC3H17 -overexpressing transgenic plants (OXs) were more tolerant under NaCl and MV treatment conditions than the wild type (WT). atc3h17 mutants were more sensitive under NaCl and MV treatment conditions compared with the WT. The transcription of the salt stress-responsive genes in ABA-dependent pathway, such as RAB18 , COR15A , and RD22 , was significantly higher in AtC3H17 OXs than in WT both under NaCl-free condition and after NaCl treatment. Our results demonstrate that AtC3H17 functions as a positive regulator in salt stress response, via the up-regulation of ABA-dependent salt stress-response pathway. [ABSTRACT FROM AUTHOR]

Abstract: Various transcription factors are involved in the response to environmental stresses in plants. In this study, we characterized AtERF71/HRE2, a member of the Arabidopsis AP2/ERF family, as an important regulator of the osmotic and hypoxic stress responses in plants. Transcript level of AtERF71/HRE2 was highly increased by anoxia, NaCl, mannitol, ABA, and MV treatments. aterf71/hre2 loss-of-function mutants displayed higher sensitivity to osmotic stress such as high salt and mannitol, accumulating higher levels of ROS under high salt treatment. In contrast, AtERF71/HRE2-overexpressing transgenic plants showed tolerance to salt and mannitol as well as flooding and MV stresses, exhibiting lower levels of ROS under high salt treatment. AtERF71/HRE2 protein was localized in the nucleus, and the C-terminal region of AtERF71/HRE2 was required for transcription activation activity. Taken together, our results suggest that AtERF71/HRE2 might function as a transcription factor involved in the response to osmotic stress as well as hypoxia. [Copyright &y& Elsevier]

Abstract: Plants have developed disparate regulatory pathways to adapt to environmental stresses. In this study, we identified MKK4 as an important mediator of plant response to osmotic stress. mkk4 mutants were more sensitive to high salt concentration than WT plants, exhibiting higher water-loss rates under dehydration conditions and additionally accumulating high levels of ROS. In contrast, MKK4-overexpressing transgenic plants showed tolerance to high salt as well as lower water-loss rates under dehydration conditions. In-gel kinase assays revealed that MKK4 regulates the activity of MPK3 upon NaCl exposure. Semi-quantitative RT-PCR analysis showed that expression of NCED3 and RD29A was lower and higher in mkk4 mutants and MKK4-overexpressing transgenic plants, respectively. Taken together, our results suggest that MKK4 is involved in the osmotic-stress response via its regulation of MPK3 activity. [Copyright &y& Elsevier]

Abstract: To investigate ternary MADS protein complexes involved in the regulation of floral organ development in rice, we identified MADS proteins interacting with the class B MADS heterodimers, OsMADS16–OsMADS4 and OsMADS16–OsMADS2, using yeast three-hybrid assay. The class B heterodimers interacted with OsMADS6, 7, 8, 14 and 17, which belong to AP1-like, SEP-like or AGL6-like MADS proteins, generating ternary complexes. The entire region of the K and C domains of OsMADS4 was required for the formation of the OsMADS16–OsMADS4–OsMADS6 and OsMADS16–OsMADS4–OsMADS7 ternary complexes. Analysis results of transgenic plants concomitantly suppressing OsMADS4 and OsMADS6, together with the results of previous studies, suggest that the OsMADS16–OsMADS4–OsMADS6 ternary complex plays an important role in floral development, especially lodicule development. [ABSTRACT FROM AUTHOR]

Abstract: Excessive light can be harmful to photosynthetic apparatus since it causes photoinhibition and photooxidation, and plants often encounter hypoxic or anoxic environments when they become submerged by heavy rain or an ensuing flood. In this study, Oryza sativa Differentially Expressed Genes (OsDEGs) from rice under photooxidation and anoxia conditions were isolated using DD-PCR. Among them, OsDEG10 is predicted to encode a small RNA-binding protein (RBP) and the transcript levels of OsDEG10 strongly increased under most of abiotic stress treatments such as high light, anoxia, NaCl, ABA, MV and cold. However, the transcript levels of two rice OsDEG10 homologs were not changed under those treatments. OsDEG10 RNAi transgenic plants were more sensitive to high light and cold stresses compared to wild-type plants. Our results suggest that OsDEG10 is a small RBP involved in the response to various abiotic stresses. [Copyright &y& Elsevier]

Abstract: Zeaxanthin epoxidase (ZEP) is an enzyme important in ABA biosynthesis and in the xanthophyll cycle. ABA, a plant hormone, is a key molecule that regulates plant responses to abiotic stress, such as drought and salinity, and is required for stress tolerance. To investigate the biological roles of the Arabidopsis thaliana ZEP gene (AtZEP) in stress response, we generated transgenic plants overexpressing the AtZEP gene and analyzed their responses to salt and drought stresses. AtZEP-overexpressing plants exhibited more vigorous growth under high salt and drought treatments than wild-type plants. In addition to enhanced de novo ABA biosynthesis, AtZEP-overexpressing plants also exhibited much higher expression of the endogenous stress-responsive genes RD29A and Rab18 than wild-type plants under salt stress. Moreover, the stomatal aperture of the AtZEP-overexpressing plants was smaller than wild-type plants after exposure to light. Our results therefore indicated that AtZEP plays important roles in response to osmotic stress. [Copyright &y& Elsevier]