Isolation and characterization of the GbVIP1gene and response to Verticillium wilt in cotton and tobacco
- ZHANG Kai †,
- ZHAO Pei †,
- WANG Hongmei Email author,
- ZHAO Yunlei ,
- CHEN Wei ,
- GONG Haiyan ,
- SANG Xiaohui and
- CUI Yanli
Verticillium wilt is a serious soil-borne vascular disease that causes major losses to upland cotton (Gossypium hirutum L.) worldwidely every year. The protein VIP1 (VirE2 interaction protein 1), a bZIP transcription factor, is involved in plant response to many stress conditions, especially pathogenic bacteria. However, its roles in cotton response to Verticillium wilt are poorly understood.
The GbVIP1 gene was cloned from resistant sea-island cotton (G. barbadense) cv. Hai 7124. Expression of GbVIP1 was up-regulated by inoculation with Verticillium dahliae and exogenous treatment with ethylene. Results of virus-induced gene silencing suggested that silencing of GbVIP1 weakened cotton resistance to Verticillium wilt. The heterologous expression of GbVIP1 in tobacco showed enhanced resistance to Verticillium wilt. The PR1, PR1-like and HSP70 genes were up-regulated in GbVIP1 transgenic tobacco after Verticillium wilt infection.
Our results suggested that GbVIP1 increased plant resistance to Verticillium wilt through up-regulating expressions of PR1, PR1-like, and HSP70. These results provide new approaches to improving resistance to Verticillium wilt in upland cotton and also have great potential for disease-resistance breeding of cotton.
- Verticillium wilt
Helicoverpa armigera (Hübner) was responsible for some $500 million of damage in India in the 1997-8. Insecticide resistance levels have been monitored routinely at sites throughout the country since 1992 using discriminating dose assays. Resistance to pyrethroids is ubiquitous and stable at around 50-80% in most areas. Organophosphate and endosulfan resistance is stable at around 20-50%. Carbamate resistance is low. There is currently no significant resistance to Bt. Putting in place effective, economic, insecticide-based programmes that do not exacerbate the resistance problems, is a priority. Field trials from 1992-5 at ICRISAT developed appropriate IPM/IRM practices in pigeonpea and cotton. In 1995-6 these were taken into ‘split-plot’ IPM/IRM farmer trials in Andhra Pradesh (AP). Seed cotton yields were slightly enhanced with a 23% reduction in the number of insecticide sprays and a 57% reduction in the a.i. applied. In expanded trials in 1996-7 trials in AP and Tamil Nadu, insecticide use was reduced by over 40% and yields enhanced by 30%. Components of the package included appropriate varietal selection, seed quality and agronomy and improved spraying practices with quality materials based on scouting to simple economic thresholds. Early season spraying for sucking pests was avoided by the use of systemic seed dressings. The sequence used for bollworms was: Eggs: at low numbers – neem; at high numbers – profenofos, Larvae: 1st round: endosulfan; 2nd round OPs (quinalphos or chlorpyrifos); 3rd round, carbamates (carbaryl); 4th round – pyrethroids (cypermethrin, fenvalerate, deltamethrin or lambda cyhalothrin). In the 1997-8 season farmer participatory demonstrations were undertaken in four states (Punjab, Andhra Pradesh, Maharashtra and Tamil Nadu). In all areas spray applications were at least halved with respect to non-participating farmers and yields rose by at least a third. The work was expanded in the 1998-9 season.
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The administrative control of Pakistan Central Cotton Committee (PCCC) has been shifted from Ministry of Commerce and Textile to the Ministry of National Food Security and Research. The decision is taken by the Government keeping in view the suggestions made by a high level review committee. The decision is hoped to favorably impact cotton research and development activities at national level.
A total of 7 delegates from Burkina Faso, Chad, Mali and Benin will be visiting Pakistan from April 22 to May 05, 2018. During the stay in Pakistan delegates will make exposure visits of different cotton research Institutions, textile and garment industry and academic institutions at Lahore, Faisalabad and Multan. A full day is reserved for Pakistan Central Cotton Committee and Central Cotton Research Institute at Multan. The visit will be coordinated by Dr. Khalid Abdullah Cotton Commissioner and Vice President PCCC.
The training is offered by Government of Pakistan under the “Technical Assistance Program for C-4 Countries”
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Signature Ceremony in Multan
The MOU between ICRA and PCCC has been signed on October 9, 2017, in Multan, in the framework of a ceremony organized by PCCC to which attended around thirty participants coming from research institutes and agricultural universities.
Dr. Michel FOK, ICRA Chair visited Pakistan from 09-12.10.2017 for the MOU signing ceremony. PCCC has nominated Dr. Fiaz Ahmad, Senior Scientist of Central Cotton Research Institute, to serve as Secretary, assisted by Mr. Zahid Khan.
Dr. FOK visited cotton trials at Research Institutes, Research Labs, two agricultural Universities of Multan. He visited cotton fields of two Progressive farmers in the surroundings of Multan. He gave two lectures about the concept of climate smart agriculture and the Chinese experience in using Bt-cotton.
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Changes in the field effectiveness of insecticides for control of cotton pests in Guntur district, Andhra Pradesh, India for the period 1979-92 are documented. Since 1985, cotton yields have decreased largely as a result of over dependence on insecticides for pest management resulting in resurgence of whitefly, Bemisia tabaci, and the development of insecticide resistance in the cotton bollworm, Helicoverpa armigera. Experiments are described where it is shown that intercropping cotton with short duration legumes or fox-tail millet (Setaria italica), results in higher cotton yields than sole cotton with the benefit of additional yield from the intercrop. An integrated pest management (IPM) strategy was evaluated alongside standard farmer practice for cotton production in Guntur district and in two seasons, significantly higher yields were recorded in the IPM treatment where only five insecticide applications were made compared to the 23 applications for the farmer practice treatment.
The results presented in this paper show that many of the insect pest problems encountered in cotton crops in Guntur district, Andhra Pradesh, can be attributed to risk averse farmers over-using insecticides. Pyrethroid, organochlorine and organophosphate insecticides are now far less effective against cotton pests than they were in the early 1980s. This is largely a result of development of insecticide resistance in the major cotton pest, H. armigera and resurgence in the sucking pest complex, some of which may also be resistant to insecticides but this has not been tested in India to date.
The simple IPM trials outlined in this paper clearly show that by enhancing natural enemies in the cotton cropping system through intercropping, reduced conventional insecticide inputs and improved agronomic practices, higher cotton yields can result. Farmers would also benefit from reduced costs associated with the purchase and application of pesticides which, under current practice, are applied at least once per week and frequently up to three times per week.
The next stage of this research will be to undertake similar trials in farmers’ fields to demonstrate the benefits of IPM and encourage farmers to adopt similar practices.
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