Scarecrow Research Articles

The GRAS transcription factor PtrPAT1 of Poncirus trifoliata functions in cold tolerance and modulates glycine betaine content by regulating the BADH-like gene

Abstract GRAS, termed after GAI (gibberellic acid insensitive), RGA (repressor of GA1), and SCR (scarecrow), is a plant-specific transcription factor crucial for plant development and stress response. However, understanding of the functions played by the GRAS members and their target genes in citrus is limited. In this study, we identified a cold stress-responsive GRAS gene from Poncirus trifoliate, designated as PtrPAT1, by yeast one-hybrid library screening using the promoter of PtrBADH-l, a betaine aldehyde dehydrogenase (BADH)-like gene. PtrPAT1, belonging to the PAT1 subfamily, was localized in the nucleus and plasma membrane, exhibited transactivation activity and showed a remarkable upregulation under cold stress. Overexpression of PtrPAT1 elevated BADH activity, increased glycine betaine (GB) accumulation and conferred enhanced cold tolerance in transgenic tobacco plants compared with wild type, while downregulation in trifoliate orange by virus-induced gene silencing (VIGS) resulted in opposite trends. Furthermore, the activities of two antioxidant enzymes, including peroxidase (POD) and superoxide dismutase (SOD), were significantly increased in the overexpression plants, but remarkably decreased in the VIGS line, consistent with accumulation patterns of the reactive oxygen species (ROS). PtrPAT1 was demonstrated to interact with and activate the PtrBADH-l promoter through the putative PAT1-binding motif with the core sequence of TTTCATGT, indicating that PtrBADH-l is a target gene of PtrPAT1. Taken together, these results demonstrate that PtrPAT1 positively affects cold tolerance through the regulation of GB biosynthesis by modulating PtrBADH-l expression.

Three RLKs integrate SHR-SCR and gibberellins to regulate root ground tissue patterning in Arabidopsis thaliana.

Precise regulation of cell division is essential for proper tissue patterning in multicellular organisms. In Arabidopsis, the ground tissue (GT) comprises cortex and endodermis in the early stages of root development. During GT maturation, additional periclinal cell divisions (PCDs) occasionally occur of the endodermis, generating a middle cortex (MC) layer between the cortex and endodermis. Although several regulatory proteins and phytohormones were identified to mediate GT patterning, such as SHORT-ROOT (SHR), SCARECROW (SCR), CYCLIND6;1 (CYCD6;1), and gibberellins (GAs), the interrelationship among these factors is not elucidated. Here, we report that three closely related receptor-like kinases (RLKs), ARH1, FEI1, and FEI2, play crucial roles in mediating a signal transduction pathway from the SHR-SCR module to GA to regulate GT patterning. Two independent triple mutants of these RLKs (tri-1 and tri-2) exhibit increased MC formation compared with wild type. Genetic analysis indicated that all three RLKs regulate MC formation mainly in a cell-autonomous manner. The transcription levels of these RLKs are negatively controlled by SHR and SCR. The altered GT patterns in shr and scr can be partially complemented by tri-1. GA biosynthesis is significantly reduced in the roots of tri-1. The excessive MC formation in tri-1 can be greatly suppressed by the exogenous application of GA3 or by the mutation of CYCD6;1. Our results demonstrate a signaling pathway involving SHR/SCR-ARH1/FEI1/FEI2-GA-CYCD6;1 to govern GT patterning in Arabidopsis thaliana.

SUPPRESSOR OF FRIGIDA 4 cooperates with the histone methylation reader EBS to positively regulate root development.

Maintenance and homeostasis of the quiescent center (QC) in Arabidopsis (Arabidopsis thaliana) root apical meristems are critical for stem cell organization and root development. Despite great progress in relevant research, the molecular mechanisms that determine the root stem cell fate and QC still need further exploration. In Arabidopsis, SUPPRESSOR OF FRIGIDA 4 (SUF4) encodes a C2H2-type zinc finger protein that represses flowering by transcriptional activation of FLOWERING LOCUS C (FLC) through the FRIGIDA (FRI) pathway, and EARLY BOLTING IN SHORT DAYS (EBS) is a bivalent histone reader that prevents premature flowering. Here, we found that SUF4 directly interacts with EBS in vivo and in vitro. Loss of function of SUF4 and/or EBS resulted in disorganization of the QC, aberrant cell division, and stunted root growth. RNA-seq and reverse transcription quantitative real-time polymerase chain reaction analysis revealed that SUF4 and EBS coregulate many root development-related genes. A series of biochemical analyses demonstrated that SUF4 directly binds to the promoter of SCARECROW (SCR), which encodes a key regulator of root development. Chromatin immunoprecipitation assay indicated that both SUF4 and EBS are recruited to the SCR locus in an interdependent manner to promote H3K4me3 levels and suppress H3K27me3 levels, thereby activating the expression of SCR. These findings improve our understanding of the function of SUF4 and EBS and provide insights into the molecular mechanism that couples a transcription factor and a histone methylation reader to modulate QC specification and root development in Arabidopsis.

Hydrogen Peroxide Signaling in the Maintenance of Plant Root Apical Meristem Activity.

Hydrogen peroxide (H2O2) is a prevalent reactive oxygen species (ROS) found in cells and takes a central role in plant development and stress adaptation. The root apical meristem (RAM) has evolved strong plasticity to adapt to complex and changing environmental conditions. Recent advances have made great progress in explaining the mechanism of key factors, such as auxin, WUSCHEL-RELATED HOMEOBOX 5 (WOX5), PLETHORA (PLT), SHORTROOT (SHR), and SCARECROW (SCR), in the regulation of RAM activity maintenance. H2O2 functions as an emerging signaling molecule to control the quiescent center (QC) specification and stem cell niche (SCN) activity. Auxin is a key signal for the regulation of RAM maintenance, which largely depends on the formation of auxin regional gradients. H2O2 regulates the auxin gradients by the modulation of intercellular transport. H2O2 also modulates the expression of WOX5, PLTs, SHR, and SCR to maintain RAM activity. The present review is dedicated to summarizing the key factors in the regulation of RAM activity and discussing the signaling transduction of H2O2 in the maintenance of RAM activity. H2O2 is a significant signal for plant development and environmental adaptation.

PpSCARECROW1 (PpSCR1) regulates leaf blade and mid-vein development in Physcomitrium patens.

In plants, asymmetric cell divisions result in distinct cell fates forming large and small daughter cells, adding to the cellular diversity in an organ. SCARECROW (SCR), a GRAS domain-containing transcription factor controls asymmetric periclinal cell divisions in flowering plants by governing radial patterning of ground tissue in roots and cell proliferation in leaves. Though SCR homologs are present across land plant lineages, the current understanding of their role in cellular patterning and leaf development is mostly limited to flowering plants. Our phylogenetic analysis identified three SCR homologs in moss Physcomitrium patens, amongst which PpSCR1 showed highest expression in gametophores and its promoter activity was prominent at the mid-vein and the flanking leaf blade cells pointing towards its role in leaf development. Notably, out of the three SCR homologs, only the ppscr1 knock-out lines developed slender leaves with four times narrower leaf blade and three times thicker mid-vein. Detailed histology studies revealed that slender leaf phenotype is either due to the loss of anticlinal cell divisions or failure of periclinal division suppression in the leaf blade. RNA-Seq analyses revealed that genes responsible for cell division and differentiation are expressed differentially in the mutant. PpSCR1 overexpression lines exhibited significantly wider leaf lamina, further reconfirming the role in leaf development. Together, our data suggests that PpSCR1 is involved in the leaf blade and mid-vein development of moss and that its role in the regulation of cell division and proliferation is ancient and conserved among flowering plants and mosses.

SHR and SCR coordinate root patterning and growth early in the cell cycle

Precise control of cell division is essential for proper patterning and growth during the development of multicellular organisms. Coordination of formative divisions that generate new tissue patterns with proliferative divisions that promote growth is poorly understood. SHORTROOT (SHR) and SCARECROW (SCR) are transcription factors that are required for formative divisions in the stem cell niche of Arabidopsis roots1,2. Here we show that levels of SHR and SCR early in the cell cycle determine the orientation of the division plane, resulting in either formative or proliferative cell division. We used 4D quantitative, long-term and frequent (every 15 min for up to 48 h) light sheet and confocal microscopy to probe the dynamics of SHR and SCR in tandem within single cells of living roots. Directly controlling their dynamics with an SHR induction system enabled us to challenge an existing bistable model3 of the SHR–SCR gene-regulatory network and to identify key features that are essential for rescue of formative divisions in shr mutants. SHR and SCR kinetics do not align with the expected behaviour of a bistable system, and only low transient levels, present early in the cell cycle, are required for formative divisions. These results reveal an uncharacterized mechanism by which developmental regulators directly coordinate patterning and growth.

The Arabidopsis SHORTROOT network coordinates shoot apical meristem development with auxin-dependent lateral organ initiation.

Plants produce new organs post-embryonically throughout their entire life cycle. This is due to stem cells present in the shoot and root apical meristems, the SAM and RAM, respectively. In the SAM, stem cells are located in the central zone where they divide slowly. Stem cell daughters are displaced laterally and enter the peripheral zone, where their mitotic activity increases and lateral organ primordia are formed. How the spatial arrangement of these different domains is initiated and controlled during SAM growth and development, and how sites of lateral organ primordia are determined in the peripheral zone is not yet completely understood. We found that the SHORTROOT (SHR) transcription factor together with its target transcription factors SCARECROW (SCR), SCARECROW-LIKE23 (SCL23) and JACKDAW (JKD), promotes formation of lateral organs and controls shoot meristem size. SHR, SCR, SCL23, and JKD are expressed in distinct, but partially overlapping patterns in the SAM. They can physically interact and activate expression of key cell cycle regulators such as CYCLIND6;1 (CYCD6;1) to promote the formation of new cell layers. In the peripheral zone, auxin accumulates at sites of lateral organ primordia initiation and activates SHR expression via the auxin response factor MONOPTEROS (MP) and auxin response elements in the SHR promoter. In the central zone, the SHR-target SCL23 physically interacts with the key stem cell regulator WUSCHEL (WUS) to promote stem cell fate. Both SCL23 and WUS expression are subject to negative feedback regulation from stem cells through the CLAVATA signaling pathway. Together, our findings illustrate how SHR-dependent transcription factor complexes act in different domains of the shoot meristem to mediate cell division and auxin dependent organ initiation in the peripheral zone, and coordinate this activity with stem cell maintenance in the central zone of the SAM.

Spatial transcriptomics of a lycophyte root sheds light on root evolution

Plant roots originated independently in lycophytes and euphyllophytes, whereas early vascular plants were rootless. The organization of the root apical meristem in euphyllophytes is well documented, especially in the model plant Arabidopsis. However, little is known about lycophyte roots and their molecular innovations during evolution. In this study, spatial transcriptomics was used to detect 97 root-related genes in the roots of the lycophyte Selaginella moellendorffii. A high number of genes showed expression patterns similar to what has been reported for seed plants, supporting the idea of a highly convergent evolution of mechanisms to control root development. Interaction and complementation data of SHORTROOT (SHR) and SCARECROW (SCR) homologs, furthermore, support a comparable regulation of the ground tissue (GT) between euphyllophytes and lycophytes. Root cap formation, in contrast, appears to be differently regulated. Several experiments indicated an important role of the WUSCHEL-RELATED HOMEOBOX13 gene SmWOX13a in Selaginella root cap formation. In contrast to multiple Arabidopsis WOX paralogs, SmWOX13a is able to induce root cap cells in Arabidopsis and has functionally conserved homologs in the fern Ceratopteris richardii. Lycophytes and a part of the euphyllophytes, therefore, may share a common mechanism regulating root cap formation, which was diversified or lost during seed plant evolution. In summary, we here provide a new spatial data resource for the Selaginella root, which in general advocates for conserved mechanisms to regulate root development but shows a clear divergence in the control of root cap formation, with a novel putative role of WOX genes in root cap formation in non-seed plants.

CRISPR/Cas9 Based Cell-Type Specific Gene Knock-Out in Arabidopsis Roots.

CRISPR/Cas9 (hereafter Cas9)-mediated gene knockout is one of the most important tools for studying gene function. However, many genes in plants play distinct roles in different cell types. Engineering the currently used Cas9 system to achieve cell-type-specific knockout of functional genes is useful for addressing the cell-specific functions of genes. Here we employed the cell-specific promoters of the WUSCHEL RELATED HOMEOBOX 5 (WOX5), CYCLIND6;1 (CYCD6;1), and ENDODERMIS7 (EN7) genes to drive the Cas9 element, allowing tissue-specific targeting of the genes of interest. We designed the reporters to verify the tissue-specific gene knockout in vivo. Our observation of the developmental phenotypes provides strong evidence for the involvement of SCARECROW (SCR) and GIBBERELLIC ACID INSENSITIVE (GAI) in the development of quiescent center (QC) and endodermal cells. This system overcomes the limitations of traditional plant mutagenesis techniques, which often result in embryonic lethality or pleiotropic phenotypes. By allowing cell-type-specific manipulation, this system has great potential to help us better understand the spatiotemporal functions of genes during plant development.

Mutations in NAKED-ENDOSPERM IDD genes reveal functional interactions with SCARECROW during leaf patterning in C4 grasses.

Leaves comprise a number of different cell-types that are patterned in the context of either the epidermal or inner cell layers. In grass leaves, two distinct anatomies develop in the inner leaf tissues depending on whether the leaf carries out C3 or C4 photosynthesis. In both cases a series of parallel veins develops that extends from the leaf base to the tip but in ancestral C3 species veins are separated by a greater number of intervening mesophyll cells than in derived C4 species. We have previously demonstrated that the GRAS transcription factor SCARECROW (SCR) regulates the number of photosynthetic mesophyll cells that form between veins in the leaves of the C4 species maize, whereas it regulates the formation of stomata in the epidermal leaf layer in the C3 species rice. Here we show that SCR is required for inner leaf patterning in the C4 species Setaria viridis but in this species the presumed ancestral stomatal patterning role is also retained. Through a comparative mutant analysis between maize, setaria and rice we further demonstrate that loss of NAKED-ENDOSPERM (NKD) INDETERMINATE DOMAIN (IDD) protein function exacerbates loss of function scr phenotypes in the inner leaf tissues of maize and setaria but not rice. Specifically, in both setaria and maize, scr;nkd mutants exhibit an increased proportion of fused veins with no intervening mesophyll cells. Thus, combined action of SCR and NKD may control how many mesophyll cells are specified between veins in the leaves of C4 but not C3 grasses. Together our results provide insight into the evolution of cell patterning in grass leaves and demonstrate a novel patterning role for IDD genes in C4 leaves.

SCARECROW maintains the stem cell niche in Arabidopsis roots by ensuring telomere integrity.

Stem cells are the ultimate source of cells for various tissues and organs and thus are essential for postembryonic plant growth and development. SCARECROW (SCR) is a plant-specific transcription regulator well known for its role in stem cell renewal in plant roots, but the mechanism by which SCR exerts this function remains unclear. To address this question, we carried out a genetic screen for mutants that no longer express SCR in the stem cell niche of Arabidopsis (Arabidopsis thaliana) roots and characterized 1 of these mutants. Molecular genetics methods allowed us to pinpoint the causal mutation in this mutant in TELOMERIC PATHWAYS IN ASSOCIATION WITH STN 1 (TEN1), encoding a factor that protects telomere ends. Interestingly, TEN1 expression was dramatically reduced in the scr mutant. Telomerase and STN1 and CONSERVED TELOMERE MAINTENANCE COMPONENT 1 (CTC1), components of the same protein complex as TEN1, were also dramatically downregulated in scr. Loss of STN1, CTC1, and telomerase caused defects in root stem cells. These results together suggest that SCR maintains root stem cells by promoting expression of genes that ensure genome integrity. Supporting this conclusion, we demonstrated that the scr mutant accumulates more DNA damage than wild-type Arabidopsis and that this problem is aggravated after exposure to zeocin, a DNA damage reagent. Finally, we identified 2 previously uncharacterized motifs in TEN1 and provide evidence that a conserved amino acid residue in 1 of the motifs is indispensable for TEN1 function. SCR thus provides a connection between genome integrity and stem cell maintenance in Arabidopsis roots.

Developmental trajectory of pluripotent stem cell establishment in Arabidopsis callus guided by a quiescent center-related gene network.

In plant tissue culture, callus formation is induced by a high auxin concentration. Among the three cell layers (the outer, middle and inner cell layers) of the callus, pluripotency acquisition in the middle cell layer is required for the potential ability of the callus to regenerate organs. Here, we reveal the developmental trajectory of middle cell layer initiation and maintenance in callus tissue originating from Arabidopsis thaliana hypocotyls. The S phase of the cell cycle is essential for the expression of quiescent center-related SCARECROW (SCR), PLETHORA1 (PLT1) and WUSCHEL-RELATED HOMEOBOX5 (WOX5) genes during the division of callus founder cells to initiate the callus primordium. After callus initiation, SHOOT-ROOT (SHR) proteins move from the inner to the middle cell layer and act together with SCR to promote the expression of PLT1 and WOX5. WOX5 represses the expression of VASCULAR-RELATED NAC-DOMAIN (VND) genes, thereby preventing callus tissue from differentiating into xylem cells. PLT1 and PLT2 directly activate JACKDAW (JKD), which is necessary for pluripotency acquisition in the middle cell layer. We hypothesize that the middle cell layer could have pluripotent stem cell activity and its establishment requires the quiescent center-related SCR-SHR-WOX5-PLT1/2-JKD gene network.

NAC1 regulates root ground tissue maturation by coordinating with the SCR/SHR–CYCD6;1 module in Arabidopsis

Precise spatiotemporal control of the timing and extent of asymmetric cell divisions (ACDs) is essential for plant development. In the Arabidopsis root, ground tissue maturation involves an additional ACD of the endodermis that maintains the inner cell layer as the endodermis and generates the middle cortex to the outside. Through regulation of the cell cycle regulator CYCLIND6;1 (CYCD6;1), the transcription factors SCARECROW (SCR) and SHORT-ROOT (SHR) play critical roles in this process. In the present study, we found that loss of function of NAC1, a NAC transcription factor family gene, causes markedly increased periclinal cell divisions in the root endodermis. Importantly, NAC1 directly represses the transcription of CYCD6;1 by recruiting the co-repressor TOPLESS (TPL), creating a fine-tuned mechanism to maintain proper root ground tissue patterning by limiting production of middle cortex cells. Biochemical and genetic analyses further showed that NAC1 physically interacts with SCR and SHR to restrict excessive periclinal cell divisions in the endodermis during root middle cortex formation. Although NAC1–TPL is recruited to the CYCD6;1 promoter and represses its transcription in an SCR-dependent manner, NAC1 and SHR antagonize each other to regulate the expression of CYCD6;1. Collectively, our study provides mechanistic insights into how the NAC1–TPL module integrates with the master transcriptional regulators SCR and SHR to control root ground tissue patterning by fine-tuning spatiotemporal expression of CYCD6;1 in Arabidopsis.

GRAS transcription factors regulate cell division planes in moss overriding the default rule

Plant cells are surrounded by a cell wall and do not migrate, which makes the regulation of cell division orientation crucial for development. Regulatory mechanisms controlling cell division orientation may have contributed to the evolution of body organization in land plants. The GRAS family of transcription factors was transferred horizontally from soil bacteria to an algal common ancestor of land plants. SHORTROOT (SHR) and SCARECROW (SCR) genes in this family regulate formative periclinal cell divisions in the roots of flowering plants, but their roles in nonflowering plants and their evolution have not been studied in relation to body organization. Here, we show that SHR cell autonomously inhibits formative periclinal cell divisions indispensable for leaf vein formation in the moss Physcomitrium patens, and SHR expression is positively and negatively regulated by SCR and the GRAS member LATERAL SUPPRESSOR, respectively. While precursor cells of a leaf vein lacking SHR usually follow the geometry rule of dividing along the division plane with the minimum surface area, SHR overrides this rule and forces cells to divide nonpericlinally. Together, these results imply that these bacterially derived GRAS transcription factors were involved in the establishment of the genetic regulatory networks modulating cell division orientation in the common ancestor of land plants and were later adapted to function in flowering plant and moss lineages for their specific body organizations.

Detecting Protein-Protein Interactions Using Bimolecular Fluorescence Complementation (BiFC) and Luciferase Complementation Assays (LCA).

In multicellular organisms, establishing the full body plane involves cell-cell signaling where protein associations are important for the diverse cellular functions within the cells. For the study of protein-protein interactions (PPI), bimolecular fluorescence complementation (BiFC) and luciferase complementation assays (LCA) have proven to be reliable tools that can be used to confirm the physical association of two proteins in a semi-in vivo environment. This chapter provides a detailed description of these two techniques using Nicotiana benthamiana as a semi-in vivo transient expression system. As an example, we will use the interaction of the two well-described transcription factors SHORT-ROOT (SHR) and SCARECROW (SCR), which are known as regulators of asymmetric cell division and stem cell specification in the root meristem of the model plant Arabidopsis thaliana. While the BiFC assay provides subcellular information by displaying a fluorescence signal, nuclear in this case, resulting from the reconstituted fluorophore, the LCA generates a quantitative readout of the SCR-SHR interaction. The combination of both assays provides information on the localization and strength of the PPI.

SHORT-ROOT and SCARECROW homologs regulate patterning of diverse cell types within and between species.

The roles of SHORT-ROOT (SHR) and SCARECROW (SCR) in ground tissue patterning and differentiation have been well established in the root of Arabidopsis thaliana. Recently, work in additional organs and species revealed the extensive functional diversification of these genes, including regulation of cortical divisions essential for nodule organogenesis in legume roots, bundle sheath specification in the Arabidopsis leaf, patterning of inner leaf cell layers in maize, and stomatal development in rice. The co-option of distinct functions and cell types is attributed to different mechanisms, including paralog retention, spatiotemporal changes in gene expression, and novel protein functions. Elaborating our knowledge of the SHR-SCR module further unravels the developmental regulation that controls diverse forms and functions within and between species.

(Don't) Look Up!: Is short-root just a short-root plant?

SHORT-ROOT (SHR) is a mobile transcription factor that plays important roles in ground tissue patterning, stem cell niche specification and maintenance, and vascular development in Arabidopsis roots. Although mRNA and protein of SHR are also found in hypocotyls, inflorescence stems, and leaves, its role in the above-ground organs has been less explored. In most developmental cases, SHR, together with its partner SCARECROW (SCR), regulates the expression of downstream target genes in controlling formative and proliferative cell divisions. Accumulating evidence on the regulatory role of SHR in shoots suggests that SHR may also play key roles in the above-ground organs. Interestingly, recent work has provided new evidence that SHR is also required for cell elongation in the hypocotyl of the etiolated seedling. This suggests that the novel roles of SHR and SHR-mediated regulatory networks can be found in shoots. Furthermore, comparative research on SHR function in roots and shoots will broaden and deepen our understanding of plant growth and development.

SCR Suppressor Mutants: Role in Hypocotyl Gravitropism and Root Growth in Arabidopsis thaliana

The SCARECROW (SCR) transcription factor plays a key role in plant growth and development. However, we know very little about the role of SCR regulated pathways in plant development. Here, we used the homozygous scr1 mutant Arabidopsis thaliana (Wassilewskija ecotype), which had a T-DNA insertion in the SCR coding region and lacks a detectable SCR transcript. This scr1 mutant has a determinate mode of root growth, shoot agravitropism and abnormal internal architecture in all organs examined. To screen for mutants that suppress the scr1 abnormal phenotypes, we exposed homozygous scr1 seeds to ethyl methane sulphonate (EMS) mutagen. Upon growth out of these mutagenized seeds, thirteen suppressor mutant-harboring strains were identified. All thirteen suppressor-harboring strains were homozygous for scr1 and lacked the SCR transcript. Ten scr hypocotyl gravitropic suppressor lines showed improved hypocotyl gravitropic response. These ten suppressors fall into six complementation groups suggesting six different gene loci. Similarly, three independent scr root length suppressor lines rescued only the root growth phenotype and fell into three complementation groups, suggesting the involvement of three different gene loci. These suppressors might identify novel functions of the SCR gene in plant development.

WARTHOG-HUMAN CONFLICTS IN BORGU SECTOR OF KAINJI LAKE NATIONAL PARK, NIGERIA

This study assessed the impacts of common Warthogs (Phacochoerus africanus) on farm crops around Borgu sector of Kainji Lake National Park, Nigeria. Data was obtained with the aid of structured questionnaire in six communities which were purposively selected (Woro, Kemenji, Worumakoto, Maji, Venira and Kanikoko) and questionnaire was randomly administered to the identified farmers. The sample size was put at one hundred and twenty (120) respondents, of which eighty one (81) questionnaires were retrieved. The demographic characteristics of the respondents indicated that age group 31-40 years recorded the highest (39.5%). The finding further revealed that 64.2% of the respondents are Muslim and 65.4% are married. Also majority of the respondents (53.1%) had stay in the study area between 6-10 years. Majority of the respondents agrees that there is presence of Warthog around their farms. The types of crops cultivated by the respondents are Maize, Guinea corn, Rice etc. Majority of the respondents indicated that they have experience crop raiding by Warthog. Types of crops preferred by Common Warthogs showed that Maize is the most preferred. The season of intense crops raiding is the raining season. The various preventive method used by the respondents to prevent Warthogs crop raiding are watch guarding, scare crow and fire/smoke. The possible solution as suggested on how to prevent Warthog-farmers conflicts are compensation and employment. This study confirms that Warthog has an impact of farm lands in the study area by causing much damage on farmer’s crops.

Human-Hippo Relationship in Selected Communities around Kainji Dam in New-Bussa, Niger State, Nigeria

Human-wildlife conflicts have become a significant issue in conservation and land management of a protected area. The study examines Hippo-Human relationship in selected communities around Kainji dam in New Bussa, Niger State, Nigeria. Data for the study was collected through pre tested structured questionnaires and analyzed using descriptive statistics. Findings from the results revealed that male Hippopotamus is the highest with 75.0% and that 37% were 50 years and above. Majority of the respondents had no formal education (42.0%). 79% of the respondents recorded that Hippopotamus was present in the study area while 82.0% have had to encounter Hippopotamus attack. The crops that are mostly grown by the respondents in the study area are Maize, Beans, Millet, Guinea corn, Rice and Groundnut. In which maize is the mostly grown and raided by Hippopotamus. The findings revealed that 69.0% of the respondents state that crop raiding is the major conflict. Various preventive measures undertaken include: fire and smoke, watch guarding, trapping, scare crow, thorn fencing and hunting, with fire and smoke being the most preferred by the respondents. The victims of these attacks are willing to prevent the attacks with fire and smoke as against killing the Hippopotamus, they should be encourage by factoring compensation into conservation policy to promote the conservation of this species in the study area.