Genome-wide analysis of annexin gene family in Schrenkiella parvula and Eutrema salsugineum suggests their roles in salt stress response

Annexins (Anns) play an important role in plant development, growth and responses to various stresses. Although Ann genes have been characterized in some plants, their role in adaptation mechanisms and tolerance to environmental stresses have not been studied in extremophile plants. In this study, Ann genes in Schrenkiella parvula and Eutrema salsugineum were identified using a genome-wide method and phylogenetic relationships, subcellular distribution, gene structures, conserved residues and motifs and also promoter prediction have been studied through bioinformatics analysis. We identified ten and eight encoding putative Ann genes in S. parvula and E. salsugineum genome respectively, which were divided into six subfamilies according to phylogenetic relationships. By observing conservation in gene structures and protein motifs we found that the majority of Ann members in two extremophile plants are similar. Furthermore, promoter analysis revealed a greater number of GATA, Dof, bHLH and NAC transcription factor binding sites, as well as ABRE, ABRE3a, ABRE4, MYB and Myc cis-acting elements in compare to Arabidopsis thaliana. To gain additional insight into the putative roles of candidate Ann genes, the expression of SpAnn1, SpAnn2 and SpAnn6 in S. parvula was studied in response to salt stress, which indicated that their expression level in shoot increased. Similarly, salt stress induced expression of EsAnn1, 5 and 7, in roots and EsAnn1, 2 and 5 in leaves of E. salsugineum. Our comparative analysis implies that both halophytes have different regulatory mechanisms compared to A. thaliana and suggest SpAnn2 gene play important roles in mediating salt stress

Determining Cytological Developments of Microspore in Four Varieties of Tomato (Lycopersicum esculentum Mill)

Introduction: Homozygous doubled haploid lines production through induction of androgenesis is a promising method to accelerate the classical breeding program. However, this technology is relatively under - developed in tomato so that improvements in methodology are required. Tomato (Lycopersicon esculentum Mill) is one of the most important vegetables which in addition of it is importance as a food, is utilized as a model plant for cytological and cytogenetic studies. Tomato breeding programs are often based on the production and selection of hybrid plants. To produce hybrid plants and application of features that is needed to breed pure lines with high specific combining abilities, new technologies such as doubled haploid production through induction of androgenesis can be an effective strategy to provide pure lines in tomato. One of the critical factors for induction of androgenesis in tomato is to use of microspores being in appropriate developmental stage. Cytological examination is one of the most accurate methods for determining the correct stage of microspore development. In this study, a number of characteristics were evaluated including the cytological properties of normal microspores development and pollen grains as well as the relationship between length of flower bud and anther length. Materials and Methods: In this study, four varieties of tomato including Mobil - Netherlands, Baker, U. S. Agriseed and Khoram were chosen. To determine the appropriate stage of microspore development for Anther culture, cytologycal studies were accomplished at different size length of flower buds (2. 0 - 7. 9 mm). Collection of flower buds to conduct experiments was done during 10 - 40 days after flowering for each cultivar. Flower buds collected early in the morning hours and within the containers closed - door ice were transported to the laboratory. To investigate the correlation between the length of flower bud and anther length, randomly selected from within each group of three flower buds, and their length was measurement. Then anthers were removed and anther length was measured for each flower buds. A total of 240 anthers, sixty anthers from each cultivar, were examined by microscope. In order to examine the development stage of microspores and pollen grains, flower buds at different length (5 - 10 mm) were calculated. Flower buds were incubated at 4 oC for 15 minutes and stained in acetocarmin %4 solution and squashed. In order to determine the relative frequency of each stage of the development of microspore and pollen, microspores at least 100 randomly in different parts of prepared slides were counted. Average relative frequency of different stages, meiosis, tetrads, microspores young and old and young and mature pollen grains with a standard deviation was calculated. Cytological studies were accomplished by microscopy research Olympus B X 51 and photographed by a digital camera D P 70. All analysis was conducted using statistical software JMP 8. Results and Discussion: The time of anthers collection for the induction of haploid is very crucial. In order to determine the appropriate steps to carry out pre - treatment induced changes in the normal development of microspores embryogenesis and cytological properties in various stages of division and development should be monitored. The results showed that there was a significant correlation between the length of flower bud and the anther length (r = 0.8,

The estimate of combining ability and heterosis for yield and yield components in tomato (Lycopersicon esculentum Mill.)

A study was conducted on a 10×10 diallel cross set of tomato including reciprocals to find out the extent of heterosis, combining ability for yield per plant (kg) and yield components (number of fruits per plant, individual fruit weight (g)) and locule number. Significant differences among genotypes were obtained for all of traits. The variances for general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects except the number of fruits per plant and relative magnitude of these variances indicated that additive gene effects were more prominent for all of the traits. The tomato genotype Mb3 proved to be the best general combiner for yield and number of fruits per plant

List of <i>Ann</i> genes identified in <i>A</i>. <i>thaliana</i>, <i>S</i>. <i>parvula</i> and <i>E</i>. <i>salsugineum</i>.

List of Ann genes identified in A. thaliana, S. parvula and E. salsugineum.</p

List of primers used in this study.

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List of TF binding sites in AtAnn, SpAnn and EsAnn gene promotors.

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Ka/Ks ratios of the <i>Ann</i> genes.

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MSA of AtAnn2, EsAnn2 and SpAnn2 deduced amino acid obtained by ClustalW.

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Gene ontology (GO) terms annotation of five motifs in AtAnn, SpAnn and EsAnn proteins Identified by MEME tools.

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RNA-seq results comparing expression strengths of homologs between <i>S</i>. <i>parvula</i> (Sp) and <i>A</i>. <i>thaliana</i> (At).

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