Two splice forms of OsbZIP1, a homolog of AtHY5, function to regulate skotomorphogenesis and photomorphogenesis in rice.

Plants possess well-developed light sensing mechanisms and signal transduction systems for regulating photomorphogenesis. ELONGATED HYPOCOTYL5 (HY5), a basic leucine zipper (bZIP) transcription factor, has been extensively characterized in dicots. In this study, we show that OsbZIP1 is a functional homolog of Arabidopsis (Arabidopsis thaliana) HY5 (AtHY5) and is important for light-mediated regulation of seedling and mature plant development in rice (Oryza sativa). Ectopic expression of OsbZIP1 in rice reduced plant height and leaf length without affecting plant fertility, which contrasts with OsbZIP48, a previously characterized HY5 homolog. OsbZIP1 is alternatively spliced, and the OsbZIP1.2 isoform lacking the CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1)-binding domain regulated seedling development in the dark. Rice seedlings overexpressing OsbZIP1 were shorter than the vector control under white and monochromatic light conditions, whereas RNAi knockdown seedlings displayed the opposite phenotype. While OsbZIP1.1 was light-regulated, OsbZIP1.2 showed a similar expression profile in both light and dark conditions. Due to its interaction with OsCOP1, OsbZIP1.1 undergoes 26S proteasome-mediated degradation under dark conditions. Also, OsbZIP1.1 interacted with and was phosphorylated by CASEIN KINASE2 (OsCK2α3). In contrast, OsbZIP1.2 did not show any interaction with OsCOP1 or OsCK2α3. We propose that OsbZIP1.1 likely regulates seedling development in the light, while OsbZIP1.2 is the dominant player under dark conditions. The data presented in this study reveal that AtHY5 homologs in rice have undergone neofunctionalization, and alternative splicing of OsbZIP1 has increased the repertoire of its functions.

An auxin regulated Universal stress protein (TaUSP_3B-1) interacts with TaGolS and provides tolerance under drought stress and ER stress.

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.

Ectopic overexpression of TaHsfA5 promotes thermomorphogenesis in Arabidopsis thaliana and thermotolerance in Oryza sativa.

Heat stress transcription factors (Hsfs) play an important role in regulating the heat stress response in plants. Among the Hsf family members, the group A members act upstream in initiating the response upon sensing heat stress and thus, impart thermotolerance to the plants. In the present study, wheat HsfA5 (TaHsfA5) was found to be one of the Hsfs, which was upregulated both in heat stress and during the recovery period after the stress. TaHsfA5 was found to interact with TaHsfA3 and TaHsfA4, both of which are known to positively regulate the heat stress-responsive genes. Apart from these, TaHsfA5 also interacted with TaHSBP2 protein, whose role has been implicated in attenuating the heat stress response. Further, its heterologous overexpression in Arabidopsis and Oryza sativa promoted thermotolerance in these plants. This indicated that TaHsfA5 positively regulated the heat stress response. Interestingly, the TaHsfA5 overexpression Arabidopsis plants when grown at warm temperatures showed  a hyper-thermomorphogenic response in comparison to the wild-type plants. This was found to be consistent with the higher expression of PIF4 and its target auxin-responsive genes in these transgenics in contrast to the wild-type plants. Thus, these results suggest the involvement of TaHsfA5 both in the heat stress response as well as in the thermomorphogenic response in plants.

Stress-induced F-Box protein-coding gene OsFBX257 modulates drought stress adaptations and ABA responses in rice.

F-box (FB) proteins that form part of SKP1-CUL1-F-box (SCF) type of E3 ubiquitin ligases are important components of plant growth and development. Here we characterized OsFBX257, a rice FB protein-coding gene that is differentially expressed under drought conditions and other abiotic stresses. Population genomics analysis suggest that OsFBX257 shows high allelic diversity in aus accessions and has been under positive selection in some japonica, aromatic and indica cultivars. Interestingly, allelic variation at OsFBX257 in aus cultivar Nagina22 is associated with an alternatively spliced transcript. Conserved among land plants, OsFBX257 is a component of the SCF complex, can form homomers and interact molecularly with the 14-3-3 rice proteins GF14b and GF14c. OsFBX257 is co-expressed in a network involving protein kinases and phosphatases. We show that OsFBX257 can bind the kinases OsCDPK1 and OsSAPK2, and that its phosphorylation can be reversed by phosphatase OsPP2C08. OsFBX257 expression level modulates root architecture and drought stress tolerance in rice. OsFBX257 knockdown (OsFBX257KD ) lines show reduced total root length and depth, crown root number, panicle size and survival under stress. In contrast, its overexpression (OsFBX257OE ) increases root depth, leaf and grain length, number of panicles, and grain yield in rice. OsFBX257 is a promising breeding target for alleviating drought stress-induced damage in rice.

SCFOsFBK1 E3 ligase mediates jasmonic acid-induced turnover of OsATL53 and OsCCR14 to regulate lignification of rice anthers and roots.

The rice F-box protein OsFBK1, which mediates the turnover of a cinnamoyl CoA-reductase, OsCCR14, has previously been shown to regulate anther and root lignification. Here, we identify OsATL53, a member of the ATL family of RING-H2 proteins that interacts with OsCCR14 in the cytoplasm. OsATL53 was identified in the same yeast two-hybrid library screening as reported previously for OsCCR14, and we show it to have cytoplasmic localization and E3 ligase ubiquitination properties. SCFOsFBK1 mediates turnover of OsATL53 in the cytoplasm and the nucleus, and that of OsCCR14 only in the nucleus, as shown by cell-free degradation assays. Confocal fluorescence lifetime imaging microscopy analyses demonstrate that in presence of jasmonic acid (JA), which plays a role in anther dehiscence, OsATL53-OsCCR14 undergoes conformational changes that trigger the complex to accumulate around the nuclear periphery and signals OsFBK1 to initiate degradation of the proteins in the respective cellular compartments. OsATL53 decreases the enzymatic activity of OsCCR14 and sequesters it in the cytoplasm, thereby regulating the lignification process. Transgenic rice with knockdown of OsATL53 display increased lignin deposition in the anthers and roots compared to the wild type, whilst knockdown of OsCCR14 results in decreased lignin content. Our results show that OsATL53 affects the activity of OsCCR14, and that their JA-induced degradation by SCFOsFBK1 regulates lignification of rice anthers and roots.

AtTLP2, a Tubby-like protein, plays intricate roles in abiotic stress signalling.

KEY MESSAGE: The Arabidopsis Tubby-like protein (TLP) encoding gene, AtTLP2, plays intricate roles during ABA-dependent abiotic stress signalling, particularly salt and dehydration stress responses. TLPs (Tubby-like proteins) are a small group of eukaryotic proteins characterized by the presence of a Tubby domain. The plant TLPs have been widely shown to play important roles during abiotic stress signaling. In this study, we investigated the role of an Arabidopsis TLP, AtTLP2, in mediating abiotic stress responses. Both attlp2 null mutant and overexpression (OE) lines, in Arabidopsis, were studied which indicated the role of the gene also in development. The attlp2 mutant showed an overall dwarfism, while its overexpression caused enhanced growth. AtTLP2 localized to the plasma membrane (PM) and showed nuclear translocation in response to dehydration stress. The protein interacted with ASK1 and ASK2, but failed to show transactivation activity in yeast. AtTLP2 was transcriptionally induced by stress, caused by salt, dehydration and ABA. The attlp2 mutant was insensitive to ABA, but hypersensitive to oxidative stress at all stages of growth. ABA insensitivity conferred tolerance to salt and osmotic stresses at the germination and early seedling growth stages, but caused hypersensitivity to salt and drought stresses at advanced stages of growth. The OE lines were more sensitive to ABA, causing increased sensitivity to most stresses at the seed germination stage, but conferring tolerance to salt and osmotic stresses at more advanced stages of development. The stomata of the attlp2 mutant were less responsive to ABA and H2O2, while that of the OE lines exhibited greater sensitivity. Several ABA-regulated stress responsive marker genes were found to be downregulated in the mutant, but upregulated in the OE lines. The study establishes that AtTLP2 plays intricate roles in abiotic stress signaling, and the response may be largely ABA dependent.

CRY2 gene of rice (Oryza sativa subsp. indica) encodes a blue light sensory receptor involved in regulating flowering, plant height and partial photomorphogenesis in dark.

KEY MESSAGE: OsiCRY2 is involved in light-regulated plant development and plays a role in regulating photomorphogenesis, plant height, flowering and most strikingly partial photomorphogenesis in dark. Cryptochrome 2 (CRY2), the blue/UV-A light photoreceptor in plants, has been reported to regulate photoperiod-dependent flowering and seedling photomorphogenesis (under low-intensity light). Among monocots, CRY2 has been reported from japonica rice, wheat, sorghum and barley. The two sub-species of rice, indica and japonica, exhibit a high degree of genetic variation and morphological and physiological differences. This article describes the characterization of CRY2 of indica rice (OsiCRY2). While the transcript levels of OsiCRY2 did not change significantly under blue light, its protein levels were found to decline with increased time duration under blue light. For phenotypic characterization, OsiCRY2 over-expression (OX) transgenics were generated in Oryza sativa Pusa Sugandh 2 (PS2) cultivar, a highly scented Basmati cultivar. The OsiCRY2OX transgenics displayed shorter coleoptiles and dwarfism than wild-type under blue light, white, and far-red light. Interestingly, even the dark-grown transgenics were shorter, concomitant with higher OsiCRY2 protein levels in transgenics than wild-type. Histological analysis revealed that the decrease in the length of the seedlings was due to a decrease in the length of the epidermal cells. The fully mature rice transgenics were shorter than the untransformed plants but flowered at the same time as wild-type. However, the OsiCRY2 Arabidopsis over-expressors exhibited early flowering by 10-15 days, indicating the potential and conservation of function of OsiCRY2. The whole-genome transcriptome profiling of rice transgenics revealed the differential up-regulation of several light-regulated genes in dark-grown coleoptiles. These data provide evidence that OsiCRY2 regulates photomorphogenesis, plant height, and flowering in indica rice.

Identification of universal stress proteins in wheat and functional characterization during abiotic stress.

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.

Draft genome sequence of Indian mulberry (Morus indica) provides a resource for functional and translational genomics.

Mulberry is an important crop plant for the sericulture industry. Here, we report high-quality genome sequence of a cultivated Indian mulberry (Morus indica cv K2) obtained by combining data from four different technologies, including Illumina, single-molecule real-time sequencing, chromosome conformation capture and optical mapping, with a gene completeness of 96.5%. Based on the genome sequence, we identified 49.2% of repetitive DNA and 27,435 high-confidence protein-coding genes with >90% of them supported by transcript evidence. A comparative analysis with other plant genomes identified 4.8% of species-specific genes in the M. indica genome. Transcriptome profiling revealed tissue-specific and differential expression across multiple accessions of ~4.7% and 2-5% of protein-coding genes, respectively, implicated in diverse biological processes. Whole genome resequencing of 21 accessions/species revealed ~2.5 million single nucleotide polymorphisms and ~ 0.2 million insertions/deletions. These data and results provide a comprehensive resource to accelerate the genomics research in mulberry for its improvement.

Elucidating the functional role of heat stress transcription factor A6b (TaHsfA6b) in linking heat stress response and the unfolded protein response in wheat.

KEY MESSAGE: TaHsfA6b-4D relocalizes intracellularly upon heat stress and play a significant role in linking the heat stress response to unfolded-protein response so as to maintain cellular homeostasis. Heat stress transcription factors (Hsfs) play a crucial role in protecting the plants against heat stress (HS). In case of wheat, TaHsfA6b-4D (earlier known as TaHsfA2d) has been identified as a seed preferential transcription factor and its role has been shown in various abiotic stresses such as heat, salt and drought stress. In the present study, a homeologue of TaHsfA6b gene (TaHsfA6b-4A) was identified and was found to be transcriptionally inactive but it localized to the nucleus. Interestingly, TaHsfA6b-4D localized to the endoplasmic reticulum-Golgi complex and peroxisomes under non-stress conditions, but was observed to accumulate in the nucleus upon HS. The expression of TaHsfA6b-4D was upregulated by dithiothreitol (DTT), which is a known ER stress inducer. Consistent with this, Arabidopsis transgenic plants overexpressing TaHsfA6b-4D performed better on DTT containing media, which further corroborated with the increased expression of ER stress marker genes in these transgenic plants in comparison to the wild type plants. Thus, these studies together suggest that TaHsfA6b-4D may relocalize intracellularly upon heat stress and may play a significant role in linking the unfolded-protein response with heat stress response so as to maintain protein homeostasis inside the cell under heat stress.

Characterization of Cry2 genes (CRY2a and CRY2b) of B. napus and comparative analysis of BnCRY1 and BnCRY2a in regulating seedling photomorphogenesis.

Cryptochrome 2 (CRY2) perceives blue/UV-A light and regulates photomorphogenesis in plants. However, besides Arabidopsis, CRY2 has been functionally characterized only in native species of japonica rice and tomato. In the present study, the BnCRY2a, generating a relatively longer cDNA and harboring an intron in its 5'UTR, has been characterized in detail. Western blot analysis revealed that BnCRY2a is light labile and degraded rapidly by 26S proteasome when seedlings are irradiated with blue light. For functional analysis, BnCRY2a was over-expressed in Brassica juncea, a related species more amenable to transformation. The BnCRY2a over-expression (BnCRY2aOE) transgenics developed short hypocotyl and expanded cotyledons, accumulated more anthocyanin in light-grown seedlings, and displayed early flowering on maturity. Early flowering in BnCRY2aOE transgenics was coupled with the up-regulation of many flowering-related genes such as FT. The present study also highlights the differential light sensitivity of cry1 and cry2 in controlling hypocotyl elongation growth in Brassica. BnCRY2aOE seedlings developed much shorter hypocotyl under the low-intensity of blue light, while BnCRY1OE seedling hypocotyls were shorter under the high-intensity blue light, compared to untransformed seedlings.

The heat stress transcription factor family in Aegilops tauschii: genome-wide identification and expression analysis under various abiotic stresses and light conditions.

Heat stress transcription factors (Hsfs) are known to play a vital role in protecting plants against various abiotic stresses. Among the wild wheat relatives, Aegilops tauschii offers an excellent source of abiotic stress tolerance genes for improvement of bread wheat. However, little is known about its stress tolerance mechanisms. In this study, 22 AetHsf genes were identified in the genome of Aegilops tauschii and their chromosomal location, exon-intron structures, sub-cellular localization, phylogenetic and syntenic relationship were analyzed. Based on the conserved motif analysis, these Hsfs were further divided into group A, B and C. The interaction network analysis and expression profile of AetHsfs in different tissues predicted their interaction with diverse types of proteins and suggested their involvement in different developmental processes of the plant. The promoter analysis of AetHsfs showed the presence of abiotic stress-responsive, phytohormone-responsive, plant development-related and light-related cis-elements. Thus, we investigated the expression of Hsfs in Aegilops tauchii seedlings under various abiotic stress conditions and irradiated with different monochromatic lights. Most of the AetHsfs were found to be upregulated by heat stress, while some showed expression in drought, salinity and high light stress as well. Notably, the expression pattern of various AetHsfs showed their responsiveness toward dark and various light conditions (blue red and far-red) as well. Thus, this study provides novel insights into the potential role of AetHsfs in stress and light signaling pathways, which can further facilitate understanding of the stress tolerance mechanisms in Aegilops tauschii.

Microbial Mechanisms of Heat Sensing.

Temperature is one of the ubiquitous signals that control both the development as well as virulence of various microbial species. Therefore their survival is dependent upon initiating appropriate response upon temperature fluctuations. In particular, pathogenic microbes exploit host-temperature sensing mechanisms for triggering the expression of virulence genes. Many studies have revealed that the biomolecules within a cell such as DNA, RNA, lipids and proteins help in sensing change in temperature, thereby acting as thermosensors. This review shall provide an insight into the different mechanisms of thermosensing and how they aid pathogenic microbes in host invasion.

Decoding the wheat awn transcriptome and overexpressing TaRca1ß in rice for heat stress tolerance.

KEY MESSAGE: Role of Rubisco Activase in imparting thermotolerance to the photosynthetic apparatus under high temperature. Thus, to improve the grain filling, we need to fine tune these crucial enzymes and their regulation, which directly or indirectly affect spike photosynthesis. CO2 fixation in cereals crops like bread wheat (Triticum aestivum L.) is also contributed by ear photosynthesis beside the other organs like leaves or the flag leaf. 1000-grain weight of three Indian wheat cultivars (cvs.) PBW343, K7903, and HD2329 were calculated under three treatments until maturity stage (i.e. removal of flag leaf, removal of awns and shaded spikes). We observed that awn removal showed a significant decrease in 1000-grain weight in all cultivars. To delve deeper into the biological and molecular pathways taking place underlying the awn physiology, we conducted the awn transcriptome analysis of thermosusceptible Indian wheat cv. PBW343 under heat stress (HS) at 42 °C for 2 h using RNA-sequencing (RNA-seq). Differential expression analysis revealed, 160 transcripts, out of these, 143 transcripts were significantly upregulated and 17 transcripts were repressed under HS conditions. Of these Rca1ß was selected for characterization and overexpression studies. Ectopic expression of TaRca1ß in rice transgenics indicate a direct correlation with tolerance under HS conditions. TaRca1ß provides a better photosynthate energy partitioning under HS with a significant reduction in the non-photochemical fluorescence quenching of the photosynthetic machinery.

A salicylic acid inducible mulberry WRKY transcription factor, MiWRKY53 is involved in plant defence response.

KEY MESSAGE: MiWRKY53 is expressed in response to various stresses and hormones. Although it is localized in the nucleus, it shows no transcriptional activation. Role of SA-mediated plant defence response is demonstrated. WRKY transcription factors are one the largest gene families in plants involved in almost every process in plants including development, physiological processes, and stress response. Salicylic acid (SA) is key regulator of biotic stress against various pathogens in plants acting via its multiple mechanisms to induce defence response. Herein, we have identified and functionally validated WRKY53 from mulberry (Morus indica var. K2). MiWRKY53 expressed differentially in response to different stress and hormonal treatments. MiWRKY53 belongs to group III of WKRY gene family, localized in nucleus, and lacks transcriptional activation activity in yeast. Hormone responsive behaviour of MiWRKY53 Arabidopsis overexpression (OE) transgenics preferentially was noted in root growth assay in response to Salicylic acid (SA). Arabidopsis overexpression plants also displayed alteration in leaf phenotype having wider leaves than the wild-type plants. PR-1 transcripts were higher in MiWRKY53 Arabidopsis OE plants and they displayed resistance towards biotrophic pathogen Pseudomonas syringae PstDC3000. MiWRKY53 Mulberry OE transgenics also depicted SA-responsive behaviour. Several hormones and stress-related cis-acting elements were also identified in the 1.2-Kb upstream regulatory region (URR) of MiWRKY53. Functional characterization of full-length promoter region revealed that it is induced by SA and further analysis of deletion constructs helped in the identification of minimal promoter responsible for its inducibility by SA. Altogether, the findings from this study point towards the SA preferential behaviour of MiWRKY53 and its function as regulator of plant defence response through SA-mediated mechanisms.

Genome-wide identification and expression profiling of cytosine-5 DNA methyltransferases during drought and heat stress in wheat (Triticum aestivum).

DNA methylation is a potential epigenetic mechanism that regulates genome stability, development, and stress mitigation in plants. It is mediated by cytosine-5 DNA methyltransferases (C5-MTases). We identified 52 wheat C5-MTases; and based on domain structure and phylogenetics, these 52 C5-MTases were classified into four sub-families including MET, CMT, DRM and DNMT2; and were distributed on 18 chromosomes. Cis-acting regulatory elements analysis identified abiotic stress-responsive, phytohormone-responsive, development-related and light-related elements in the promoters of TaC5-MTases. We also examined the transcript abundance of TaC5-MTases in different tissues, developmental stages and under abiotic stresses. Notably, most of the TaC5-MTases (TaCMT2, TaCMT3b, TaCMT3c, TaMET1, TaDRM10, TaDNMT2) showed differential regulation of their transcript abundance during drought and heat stress. Overall, the above results provide significant insights into the expression and the probable functions of TaC5-MTases and will also expedite future research programs to explore the mechanisms of epigenetic regulation in wheat.

Functional characterization of HSFs from wheat in response to heat and other abiotic stress conditions.

High temperature stress is known to be one of the major limiting factors for wheat productivity worldwide. HSFs are known to play a central role in heat stress response in plants. Hence, the current study is an attempt to explore an in-depth involvement of TaHSFs in stress responses mainly in heat and other abiotic responses like salinity, drought, and cold stress. Effort was made to understand as how the expression of HSF is able to define the differential robustness of wheat varieties. Subsequent studies were done to establish the involvement of any temporal or spatial cue on the behavior of these TaHSFs under heat stress conditions. A total of 53 HSFs have been reported until date and out of these, few TaHSFs including one identified in our library, i.e., TaHsfA2d (Traes_4AS_52EB860E7.2), were selected for the expression analysis studies. The expressions of these HSFs were found to differ in both magnitude and sensitivity to the heat as well as other abiotic stresses. Moreover, these TaHSFs displayed wide range of expression in different tissues like anther, ovary, lemma, palea, awn, glume, and different stages of seed development. Thus, TaHSFs appear to be under dynamic expression as they respond in a unique manner to spatial, temporal, and environmental cues. Therefore, these HSFs can be used as candidate genes for understanding the molecular mechanism under heat stress and can be utilized for improving crop yield by enhancing the tolerance and survival of the crop plants under adverse environment conditions.

Comparative transcriptomics and comprehensive marker resource development in mulberry.

BACKGROUND: High potential of Morus laevigata and Morus serrata has been proposed in the breeding programs for Morus sp. However, due to the lack of dense molecular markers this goal is still in its nascent stage and not yet realized. We thus, sequenced the transcriptomes of these two wild Morus species and utilized the data for marker development. RESULTS: We generated 87.0 and 80.3 Mb of transcriptome data from M. laevigata and M. serrata, respectively. The transcriptomes from M. laevigata and M. serrata, were assembled into 95,181 and 85,269 transcripts, respectively, and annotated. We identified around 24,049 Simple Sequence Repeats (SSRs), 1,201,326 Single Nucleotide Polymorphisms (SNPs) and 67,875 Insertion-Deletions (InDels). The variants having a higher impact were also identified and their effect was further investigated. CONCLUSIONS: The transcriptome resource from the wildly growing mulberry species developed in this study can find wide applicability in gene identification and/or characterization. It can also contribute immensely in the existing mulberry improvement programs.

Genome-wide analysis, expression dynamics and varietal comparison of NAC gene family at various developmental stages in Morus notabilis.

NAC genes are important transcription factors and forms a large family in plants. They have shown to play an important role in growth and development and have also been shown to involve in regulation of stress-responsive genes. In the present study, a repertoire of NAC genes in recently published mulberry genome has been identified which consists of a total of 79 members. Structural analysis revealed that most of the NAC genes in mulberry contain two introns. The proteins encoded by them show a wide range of isoelectric points suggestive of their varied roles in varying microcellular environment. Phylogenetic and conserved motif analysis elucidate the presence of 15 sub-groups of these genes along with two novel sub-groups having distinct conserved motifs which are not present in Arabidopsis. Gene ontology term enrichment analysis and cis-element identification from their putative 1 K upstream regulatory region indicates their possible role in important biological processes like organ formation, meristem establishment, senescence, and various biotic and abiotic stresses. Expression analysis across various developmental stages led to identification of their preferential expression in diverse tissues. Taken together, this work provides a solid background information related to structure, function, expression and evolution of NAC gene family in mulberry.