A loss-of-function mutant allele of a glycosyl hydrolase gene has been co-opted for seed weight control during soybean domestication

The resultant DNA from loss-of-function mutation can be recruited in biological evolution and development.Here,we present such a rare and potential case of“to gain by loss”as a neomorphic mutation during soybean domestication for increasing seed weight.Using a population derived from a chromosome segment substitution line of Glycine max(SN14)and Glycine soja(ZYD06),a quantitative trait locus(QTL)of 100-seed weight(q HSW)was mapped on chromosome 11,corresponding to a truncatedβ-1,3-glucosidase(βGlu)gene.The novel gene hsw results from a 14-bp deletion,causing a frameshift mutation and a premature stop codon in theβGlu.In contrast to HSW,the hsw completely lostβGlu activity and function but acquired a novel function to promote cell expansion,thus increasing seed weight.Overexpressing hsw instead of HSW produced large soybean seeds,and surprisingly,truncating hsw via gene editing further increased the seed size.We further found that the core 21-aa peptide of hsw and its variants acted as a promoter of seed size.Transcriptomic variation in these transgenic soybean lines substantiated the integration hsw into cell and seed size control.Moreover,the hsw allele underwent selection and expansion during soybean domestication and improvement.Our work cloned a likely domesticated QTL controlling soybean seed weight,revealed a novel genetic variation and mechanism in soybean domestication,and provided new insight into crop domestication and breeding,and plant evolution.

Power Distribution Strategy Considering Active Power Loss for DFIGs Wind Farm

With the development of concentrated wind power areas, new energy’s dispatching problems are more prominent with its fast expansion. However, we can maximize the utilization of wind power under power curtailment conditions by optimal wind power dispatching. The paper studies on the basic theories of wind power turbines, and analyses the power’s control and output characteristics of wind turbine, which analyses the double-fed inductor generator’s excellent decoupling control of power and its excellent reactive power output capability. By studying the characteristics of wind power output, this paper provides a strategy for optimal dispatch in wind power generation. The calculation results show that the total active and reactive power output of the wind farm match the request of dispatch center. And the total active loss and total reactive loss is the least in the meantime.

A Possible Configuration with Motor-generator Pair for Renewable Energy Integration

High penetration rates of renewable energy will bring stability problems for the future power grid.One of the critical issues is lack of inertia.In this paper,a synchronous motor-generator pair(MGP)system is proposed as a possible solution for renewable energy integration to enhance inertia and improve grid stability.First,feasibility studies of MGP on inertia,damping,efficiency,and cost are presented.Second,an analytical model is established based on its rotor angle relation.An active power control scheme based on voltage phase difference between renewable energy source and grid is then proposed,and state equations of MGP are derived for small signal stability.Next,two experiments are designed and implemented to verify stable operation and active power regulation of the MGP system.A single-machine infinite bus system is tested to investigate small signal stability and frequency response of MGP.The results show that the MGP system has a solid base in physics and is a feasible solution for providing enough inertia and improving small signal performance in the power grid with high penetration of renewable energy.The paper concludes with a discussion on future research directions to gain a better understanding of MGP.