scholarly journals Five OsS40 Family Members Are Identified as Senescence-Related Genes in Rice by Reverse Genetics Approach

2021 ◽  
Vol 12 ◽  
Author(s):  
Habiba ◽  
Jiaxuan Xu ◽  
Ahmed G. Gad ◽  
Yuling Luo ◽  
Chunlan Fan ◽  
...  

A total of 16 OsS40 genes of Oryza sativa were identified in our previous work, but their functions remain unclear. In this study, 13 OsS40 members were knocked out using the CRISPR/cas9 gene-editing technology. After screening phenotype characterization of CRISPR/Cas9 mutants compared to WT, five oss40s mutants exhibited a stay-green phenotype at 30 days after heading. Moreover, increased grain size and grain weight occurred in the oss40-1, oss40-12, and oss40-14 lines, while declined grain weight appeared in the oss40-7 and oss40-13 mutants. The transcript levels of several senescence-associated genes (SAGs), chlorophyll degradation-related genes (CDGs), as well as WRKY members were differentially decreased in the five stay-green oss40s mutants compared to WT. Five oss40 mutants also exhibited a stay-green phenotype when the detached leaves were incubated under darkness for 4 days. OsSWEET4 and OsSWEET1b were significantly upregulated, while OsSWEET1a and OsSWEET13 were significantly downregulated in both oss40-7 and oss40-14 compared to WT. Furthermore, these five OsS40 displayed strong transcriptional activation activity and were located in the nucleus. Most of the OsS40 genes were downregulated in the oss40-1, oss40-7, and oss40-12 mutants, but upregulated in the oss40-13 and oss40-14 mutants, indicating coordinated regulation among OsS40 members. These results suggest that OsS40-1, OsS40-7, OsS40-12, OsS40-13, and OsS40-14 are senescence-associated genes, involved in the senescence and carbon allocation network by modulating other OsS40 members, SWEET member genes, and senescence-related gene expression.

2016 ◽  
Vol 8 (1) ◽  
pp. 107-111
Author(s):  
Naresh Pratap Singh ◽  
Vaishali Vaishali

Stay green trait is one of the major character of the crops like wheat, rice etc. to sustain under abiotic stresses. In the present study, 10 wheat varieties were collected to develop the stay green genotype by treating them with 0.5% Ethyl methanesulphonate (EMS) for 60 minutes. The various morphological and physiological characteristics such as: plant height, leaf area, numbers of productive tillers/plant, seeds per spike, 1000 grain weight, related water content (RWC), chlorophyll content etc. were recorded under controlled and treatment conditions. Exceptionally, K 7410 and RAJ 3765 varieties showed better value of all morpho-physiological characters among all the ten wheat varieties in control and treatment like 1000 grain weight 58.50 to 60.89g and 56.89 to 58.07g etc. Such mutants of these two varieties may be considered as stay green mutants and can perform better under abiotic stress conditions like drought, high temperature.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 598
Author(s):  
Nasrein Mohamed Kamal ◽  
Yasir Serag Alnor Gorafi ◽  
Hanan Abdeltwab ◽  
Ishtiag Abdalla ◽  
Hisashi Tsujimoto ◽  
...  

Several marker-assisted selection (MAS) or backcrossing (MAB) approaches exist for polygenic trait improvement. However, the implementation of MAB remains a challenge in many breeding programs, especially in the public sector. In MAB introgression programs, which usually do not include phenotypic selection, undesired donor traits may unexpectedly turn up regardless of how expensive and theoretically powerful a backcross scheme may be. Therefore, combining genotyping and phenotyping during selection will improve understanding of QTL interactions with the environment, especially for minor alleles that maximize the phenotypic expression of the traits. Here, we describe the introgression of stay-green QTL (Stg1–Stg4) from B35 into two sorghum backgrounds through an MAB that combines genotypic and phenotypic (C-MAB) selection during early backcross cycles. The background selection step is excluded. Since it is necessary to decrease further the cost associated with molecular marker assays, the costs of C-MAB were estimated. Lines with stay-green trait and good performance were identified at an early backcross generation, backcross two (BC2). Developed BC2F4 lines were evaluated under irrigated and drought as well as three rainfed environments varied in drought timing and severity. Under drought conditions, the mean grain yield of the most C-MAB-introgression lines was consistently higher than that of the recurrent parents. This study is one of the real applications of the successful use of C-MAB for the development of drought-tolerant sorghum lines for drought-prone areas.


2002 ◽  
Vol 48 (4) ◽  
pp. 273-280 ◽  
Author(s):  
X.-B. Han ◽  
X.-C. Zhou ◽  
Z.-Y. Hu ◽  
Z.-H. Zhang ◽  
Y.-X. Liu
Keyword(s):  

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Yu-Huan Shih ◽  
Xiaolei Xu

Background: TITIN (TTN) has more than 300 exons and encodes a gigantic protein that is crucial for heart and muscle development. Mutations in TTN caused a variety of human diseases including cardiomyopathy and muscular dystrophy. Recently, dilated cardiomyopathy-associated mutations on TTN have been found more frequently in exons encoding A-band domains but less in exons encoding the N-terminal Z-disc domains, suggesting that mutations in different exons of TTN cause distinct consequences. To elucidate the underlying mechanisms, we leveraged the Transcription Activator-Like Effects Nuclease (TALEN) technology in zebrafish to introduce truncating mutations in different exons of ttn, and then study their effects on heart and somites. Results: We generated truncational mutations in different exons of zebrafish titins encoding Z-disc, N2B, Novex-3, and A domains, respectively. Because zebrafish contains two titin homologues, ttna and ttnb, we introduced mutations in both genes at the corresponding loci. While both Z-disc and A band mutations on ttna disrupted sarcomere assembly in heart and somites, Z-disc or A band mutations on ttnb only affect somites without affecting the heart. Interestingly, a Z-disc mutation on ttna resulted in milder phenotypes than an A-band mutation, while a Z-disc mutation on ttnb generated severer phenotypes than an A-band mutation. No phenotype was observed in the homozygous fish in either ttna-novex-3 or ttnb-N2B mutant fish. Conclusions: A spectrum of truncational mutations in ttna and ttnb has been generated in zebrafish using the TALEN technology. Mutations in different exons result in different phenotypes. Detailed characterization of these mutants and double mutants will be presented, which shall elicit distinct contribution of alternative splicing and exon skipping as two candidate mechanisms during pathogenesis of Titinopathies.


2021 ◽  
Vol 57 (No. 4) ◽  
pp. 279-288
Author(s):  
Jose Ignacio Ruiz de Galarreta ◽  
Alba Alvarez-Morezuelas ◽  
Nestor Alor ◽  
Leire Barandalla ◽  
Enrique Ritter

The oomycete Phytophthora infestans is responsible for the disease known as late blight in potato and tomato. It is the plant pathogen that has caused the greatest impact on humankind so far and, despite all the studies that have been made, it remains the most important in this crop. In Spain during the last years a greater severity of the disease has been observed in both, potato and tomato, probably due to genetic changes in pathogen populations described recently. The aim of this study was the characterization of the physiological strains of 52 isolates of P. infestans obtained in different potato-growing areas in Spain. For this purpose, inoculations on detached leaves were performed in order to determine compatibility or incompatibility reactions. A total of 17 physiological races were found. The less frequent virulence factors were Avr5 and Avr8. By studying the epidemiology of the pathogen, a specific breeding program for late blight resistance can be implemented.


2006 ◽  
Vol 340 (2) ◽  
pp. 386-394 ◽  
Author(s):  
M. Javier Herrero-Turrión ◽  
Mitsunori Fukuda ◽  
Faustino Mollinedo

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