Gibberellin-dependent induction of tomato extracellular invertase Lin7 is required for pollen development

2006 ◽  
Vol 33 (6) ◽  
pp. 547 ◽  
Author(s):  
Reinhard K. Proels ◽  
Mari-Cruz González ◽  
Thomas Roitsch

The tomato extracellular invertase family comprises four members with different expression patterns. Among the three invertase isoenzymes expressed in floral tissues, Lin5, Lin6 and Lin7, the expression of Lin7 was previously shown to be restricted to the tapetum and pollen. Histochemical analysis of β-glucuronidase (GUS) reporter activity shows Lin7 expression in pollen and pollen tubes of corresponding transgenic plants. The physiological relevance of the identification of gibberellin-responsive cis-acting elements for induction of the Lin7 promoter is supported by the repression of Lin7 expression in pollen grains by the gibberellin biosynthesis inhibitor paclobutrazol. Functional approaches with transgenic tomato plants establish a link between gibberellin action and invertase function in the tapetum for pollen development: both tissue-specific antisense repression of extracellular Lin7 and ectopic inactivation of the biologically active GAs by expression of a GA2-oxidase under control of the Lin7 promoter result in germination deficient pollen. These complementary findings support the idea that the GA requirement of pollen development, pollen germination and pollen tube growth are linked to energy metabolism via the regulation of an extracellular invertase as a key enzyme for carbohydrate supply via an apoplasmic pathway.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12557
Author(s):  
Jiajia Feng ◽  
Yi Chen ◽  
Xianghui Xiao ◽  
Yunfang Qu ◽  
Pengtao Li ◽  
...  

Callose deposition occurs during plant growth and development, as well as when plants are under biotic and abiotic stress. Callose synthase is a key enzyme for the synthesis of callose. In this study, 27, 28, 16, and 15 callose synthase family members were identified in Gossypium hirsutum, Gossypium barbadense, Gossypium raimondii, and Gossypium arboreum using the sequence of Arabidopsis callose synthase. The CalSs were divided into five groups by phylogenetic, gene structure, and conservative motif analysis. The conserved motifs and gene structures of CalSs in each group were highly similar. Based on the analysis of cis-acting elements, it is inferred that GhCalSs were regulated by abiotic stress. WGD/Segmental duplication promoted the amplification of the CalS gene in cotton, and purification selection had an important function in the CalS family. The transcriptome data and qRT-PCR under cold, heat, salt, and PEG treatments showed that GhCalSs were involved in abiotic stress. The expression patterns of GhCalSs were different in various tissues. We predicted that GhCalS4, which was highly expressed in fibers, had an important effect on fiber elongation. Hence, these results help us understand the role of GhCalSs in fiber development and stress response.



Author(s):  
John R. Rowley

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.



2021 ◽  
Vol 22 (9) ◽  
pp. 4634
Author(s):  
Wenxuan Du ◽  
Junfeng Yang ◽  
Lin Ma ◽  
Qian Su ◽  
Yongzhen Pang

The calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) play important roles in plant signal transduction and response to abiotic stress. Plants of Medicago genus contain many important forages, and their growth is often affected by a variety of abiotic stresses. However, studies on the CBL and CIPK family member and their function are rare in Medicago. In this study, a total of 23 CBL and 58 CIPK genes were identified from the genome of Medicago sativa as an important forage crop, and Medicaog truncatula as the model plant. Phylogenetic analysis suggested that these CBL and CIPK genes could be classified into five and seven groups, respectively. Moreover, these genes/proteins showed diverse exon-intron organizations, architectures of conserved protein motifs. Many stress-related cis-acting elements were found in their promoter region. In addition, transcriptional analyses showed that these CBL and CIPK genes exhibited distinct expression patterns in various tissues, and in response to drought, salt, and abscisic acid treatments. In particular, the expression levels of MtCIPK2 (MsCIPK3), MtCIPK17 (MsCIPK11), and MtCIPK18 (MsCIPK12) were significantly increased under PEG, NaCl, and ABA treatments. Collectively, our study suggested that CBL and CIPK genes play crucial roles in response to various abiotic stresses in Medicago.



Author(s):  
Qingchun Zhao ◽  
Zhenzhen Luo ◽  
Jiadong Chen ◽  
Hongfang Jia ◽  
Penghui Ai ◽  
...  

AbstractPhosphorus (P) deficiency is one of the major nutrient stresses restricting plant growth. The uptake of P by plants from soil is mainly mediated by the phosphate (Pi) transporters belonging to the PHT1 family. Multiple PHT1 genes from diverse plant species have been shown to be strongly up-regulated upon Pi starvation, however, the underlying mechanisms for the Pi-starvation-induced (PSI) up-regulation have not been well deciphered for most Pi transporter genes. Here, we reported a detailed dissection of the promoter activity of a PSI rice Pi transporter gene OsPT6, using the β-glucuronidase (GUS) reporter gene. OsPT6 promoter could drive GUS expression strongly in both roots and blades of rice plants grown under low P, but not high P. Cis-acting element analysis identified one copy of the P1BS motif and two copies of the W-box motif in OsPT6 promoter. Targeted deletion of the P1BS motif caused almost complete abolition of GUS induction in response to Pi starvation, irrespective of the presence or absence of the W-box motif, Four repeats of the P1BS motif fused to the CaMV35S minimal promoter was sufficient to induce GUS expression responsive to Pi starvation. Targeted deletion of the upstream W-box motif (W1) did not affect the GUS expression activity compared with the full-length OsPT6 promoter, while targeted deletion of the downstream W-box motif (W2) or both of the W-box motifs remarkably reduced the GUS induction rate upon Pi starvation. Our results proposed that the PSI response of OsPT6 was positively regulated by at least two elements, the sole P1BS and the downstream W-box, in its promoter, and the W-box-mediated up-regulation of OsPT6 might be highly dependent on the P1BS motif.



Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 249
Author(s):  
Weimiao Liu ◽  
Liai Xu ◽  
Hui Lin ◽  
Jiashu Cao

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.



BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shuo Wei ◽  
Wen Zhang ◽  
Rao Fu ◽  
Yang Zhang

Abstract Background 2-Oxoglutarate and Fe(II)-dependent dioxygenases (2ODDs) belong to the 2-oxoglutarate-dependent dioxygenase (2OGD) superfamily and are involved in various vital metabolic pathways of plants at different developmental stages. These proteins have been extensively investigated in multiple model organisms. However, these enzymes have not been systematically analyzed in tomato. In addition, type I flavone synthase (FNSI) belongs to the 2ODD family and contributes to the biosynthesis of flavones, but this protein has not been characterized in tomato. Results A total of 131 2ODDs from tomato were identified and divided into seven clades by phylogenetic classification. The Sl2ODDs in the same clade showed similar intron/exon distributions and conserved motifs. The Sl2ODDs were unevenly distributed across the 12 chromosomes, with different expression patterns among major tissues and at different developmental stages of the tomato growth cycle. We characterized several Sl2ODDs and their expression patterns involved in various metabolic pathways, such as gibberellin biosynthesis and catabolism, ethylene biosynthesis, steroidal glycoalkaloid biosynthesis, and flavonoid metabolism. We found that the Sl2ODD expression patterns were consistent with their functions during the tomato growth cycle. These results indicated the significance of Sl2ODDs in tomato growth and metabolism. Based on this genome-wide analysis of Sl2ODDs, we screened six potential FNSI genes using a phylogenetic tree and coexpression analysis. However, none of them exhibited FNSI activity. Conclusions Our study provided a comprehensive understanding of the tomato 2ODD family and demonstrated the significant roles of these family members in plant metabolism. We also suggest that no FNSI genes in tomato contribute to the biosynthesis of flavones.



Author(s):  
Zhen Tian ◽  
Xiaodong Qin ◽  
Hui Wang ◽  
Ji Li ◽  
Jinfeng Chen

AbstractThe CONSTANS-like (COL) gene family is one of the plant-specific transcription factor families that play important roles in plant growth and development. However, the knowledge of COLs related in cucumber is limited, and their biological functions, especially in the photoperiod-dependent flowering process, are still unclear. In this study, twelve CsaCOL genes were identified in the cucumber genome. Phylogenetic and conserved motif analyses provided insights into the evolutionary relationship between the CsaCOLs. Further, the comparative genome analysis revealed that COL genes are conserved in different plant species, especially collinearity gene pairs related to CsaCOL5. Ten kinds of cis-acting elements were vividly detected in CsaCOLs promoter regions, including five light-responsive elements, which echo the diurnal rhythm expression patterns of seven CsaCOL genes under SD and LD photoperiod regimes. Combined with the expression data of developmental stage, three CsaCOL genes are involved in the flowering network and play pivotal roles for the floral induction process. Our results provide useful information for further elucidating the structural characteristics, expression patterns, and biological functions of COL family genes in many plants



2005 ◽  
Vol 25 (8) ◽  
pp. 3232-3246 ◽  
Author(s):  
Tae-Don Kim ◽  
Jong-So Kim ◽  
Jong Heon Kim ◽  
Jihwan Myung ◽  
Hee-Don Chae ◽  
...  

ABSTRACT Serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase [AANAT]) is the key enzyme in melatonin synthesis regulated by circadian rhythm. To date, our understanding of the oscillatory mechanism of melatonin has been limited to autoregulatory transcriptional and posttranslational regulations of AANAT mRNA. In this study, we identify three proteins from pineal glands that associate with cis-acting elements within species-specific AANAT 3′ untranslated regions to mediate mRNA degradation. These proteins include heterogeneous nuclear ribonucleoprotein R (hnRNP R), hnRNP Q, and hnRNP L. Their RNA-destabilizing function was determined by RNA interference and overexpression approaches. Expression patterns of these factors in pineal glands display robust circadian rhythm. The enhanced levels detected after midnight correlate with an abrupt decline in AANAT mRNA level. A mathematical model for the AANAT mRNA profile and its experimental evidence with rat pinealocytes indicates that rhythmic AANAT mRNA degradation mediated by hnRNP R, hnRNP Q, and hnRNP L is a key process in the regulation of its circadian oscillation.



1979 ◽  
Vol 57 (18) ◽  
pp. 1946-1950 ◽  
Author(s):  
S. C. Agarwala ◽  
C. Chatterjee ◽  
P. N. Sharma ◽  
C. P. Sharma ◽  
N. Nautiyal

A reduction in the size of tassels, male flowers, and anthers resulted from molybdenum deficiency in maize. In molybdenum-deficient plants, anthesis was suppressed or delayed and the anthers had fewer and smaller pollen grains that lacked dense cytoplasmic contents, appeared shrivelled, and had poor viability. Because of molybdenum deficiency, there was a decrease in the activity of starch phosphorylase in mature and freshly shed pollen grains and decreases in the activities of invertase and acid phosphatase at all the five stages at which pollen grains were assayed for the enzymes. The activities of catalase and peroxidase were increased by molybdenum deficiency at all five stages and that of ribonuclease at four out of the five stages of pollen development.



Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1618
Author(s):  
Kristina Kiisholts ◽  
Kaido Kurrikoff ◽  
Piret Arukuusk ◽  
Ly Porosk ◽  
Maire Peters ◽  
...  

Gene therapy is a powerful tool for the development of new treatment strategies for various conditions, by aiming to transport biologically active nucleic acids into diseased cells. To achieve that goal, we used highly potential delivery vectors, cell-penetrating peptides (CPPs), as oligonucleotide carriers for the development of a therapeutic approach for endometriosis and cancer. Despite marked differences, both of these conditions still exhibit similarities, like excessive, uncoordinated, and autonomous cellular proliferation and invasion, accompanied by overlapping gene expression patterns. Thus, in the current study, we investigated the therapeutic effects of CPP and siRNA nanoparticles using in vitro models of benign endometriosis and malignant glioblastoma. We demonstrated that CPPs PepFect6 and NickFect70 are highly effective in transfecting cell lines, primary cell cultures, and three-dimensional spheroids. CPP nanoparticles are capable of inducing siRNA-specific knockdown of therapeutic genes, ribonucleotide reductase subunit M2 (RRM2), and vascular endothelial growth factor (VEGF), which results in the reduction of in vitro cellular proliferation, invasion, and migration. In addition, we proved that it is possible to achieve synergistic suppression of endometriosis cellular proliferation and invasion by combining gene therapy and hormonal treatment approaches by co-administering CPP/siRNA nanoparticles together with the endometriosis-drug danazol. We suggest a novel target, RRM2, for endometriosis therapy and as a proof-of-concept, we propose a CPP-mediated gene therapy approach for endometriosis and cancer.



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