During pollen tube growth, the walls of the tube provide the mechanical strength resisting turgor pressure to protect two sperm cells. Cell wall proteins may play an important role in this process. Pollen tube cell wall proteins known as leucine-rich repeat extensins (LRXs) harbor a leucine-rich repeat domain and an extensin domain. In this study, the functions of four pollen-expressed LRXs, LRX8, LRX9, LRX10, and LRX11 (LRX8-11), were characterized in Arabidopsis (). displayed a consistent expression pattern in mature pollen grains and pollen tubes. In a phenotypic analysis of four single mutants, six double mutants, four triple mutants, and a quadruple mutant, the triple and quadruple mutant plants displayed markedly reduced seed set and decreased male transmission efficiency accompanied by compromised pollen germination and pollen tube growth. GFP-fused LRX8, LRX10, and LRX11 were found to be localized to pollen tube cell walls. An immunohistochemical analysis of pollen tube cell wall polysaccharides showed an increase in the amount of rhamnogalacturonan I in the subapical walls of pollen tubes of the and mutants and a decrease in the content of fucosylated xyloglucans in compared with wild-type plants. Moreover, the callose content in the apical walls of pollen tubes increased in the mutant. In conclusion, we propose that LRX8-11 function synergistically to maintain pollen tube cell wall integrity; thus, they play critical roles in pollen germination and pollen tube growth.

No abstract

Abstract-The automated warehouse built in many enterprises still need through manual intervention or random allocation method for distribution of goods allocation. This distribution does not guarantee that the utilization rate of warehouse is high, especially when more types and a large number of goods, need more scientific and reasonable scheme for the storage of goods, and enhance great application value and practical significance for the competitiveness of enterprises. In order to improve the efficiency and utilization of automated warehouse, we take automated warehouse as the object to study the optimization of the storage location of goods based on the genetic algorithm in this paper.

SUMMARY Pollen tube integrity, growth and guidance are crucial factors in plant sexual reproduction. Members of the plant Skewed5 (SKU5) Similar (SKS) family show strong similarity to multicopper oxidases (MCOs), but they lack conserved histidines in MCO active sites. The functions of most SKS family members are unknown. Here, we show that Arabidopsis pollen‐expressed SKS11 and SKS12 play important roles in pollen tube integrity, growth and guidance. The sks11sks12 mutant exhibited significantly reduced male fertility. Most of the pollen from sks11sks12 plants burst when germinated, and the pollen tubes grew slowly and exhibited defective growth along the funiculus and micropyle. SKS11‐GFP and SKS12‐mCherry were detected at the cell wall in pollen tubes. The contents of several cell wall polysaccharides and arabinogalactans were decreased in the pollen tube cell walls of sks11sks12 plants. Staining with a reactive oxygen species (ROS)‐sensitive dye and use of the H2O2 sensor HyPer revealed that the ROS content in the pollen tubes of sks11sks12 plants was remarkably reduced. SKS11444His‐Ala, in which the last conserved histidine was mutated, could restore the mutant phenotypes of sks11sks12. Thus, SKS11/12 are required for pollen tube integrity, growth and guidance possibly by regulating the ROS level and cell wall polysaccharide deposition or remodeling in pollen tubes.

This paper deals with a single-machine resource allocation scheduling problem with learning effect and group technology. Under slack due-date assignment, our objective is to determine the optimal sequence of jobs and groups, optimal due-date assignment, and optimal resource allocation such that the weighted sum of earliness and tardiness penalties, common flow allowances, and resource consumption cost is minimized. For three special cases, it is proved that the problem can be solved in polynomial time. To solve the general case of problem, the heuristic, tabu search, and branch-and-bound algorithms are proposed.