The maize (Zea mays) stigma, which is commonly known as silk, is indispensable for reproduction and thus for grain yield. Here, we isolated a spontaneous mutant sk-A7110, which completely lacks silk; scanning electron microscopy showed that the sk-A7110 pistils degenerated during late floret differentiation. Genetic analysis confirmed that this trait was controlled by a recessive nuclear gene and sk-A7110 was mapped to a 74.13-kb region on chromosome 2 between the simple sequence repeat markers LA714 and L277. Sequence analysis of candidate genes in this interval identified a single-nucleotide insertion at position 569 downstream of the transcriptional start site in Zm00001d002970, which encodes a UDP-glycosyltransferase; this insertion produces a frameshift and premature translational termination. RNA-sequencing analysis of young ears identified 258 differentially expressed genes (DEGs) between sk-A7110 and the wild type (WT), including 119 up- and 139 down-regulated genes. Interestingly, most DEGs related to jasmonic acid (JA) synthesis were up-regulated in the mutant compared to WT. Consistent with this, the JA and JA-Isoleucine (JA-Ile) contents were significantly higher in sk-A7110 ears than in WT. At the same time, RNA-sequencing analysis of tassels showed that sk-A7110 could reduce the number of tassel branches in maize by down-regulating the expression of UB2 and UB3 genes. Our identification of the sk-A7110 mutant and the responsible gene will facilitate further studies on female infertility research or maize breeding.

Mango (Mangifera indica L.) is a widely cultivated fruit in tropical and subtropical areas at altitudes ranging from 100 to 1500 m above sea level (masl). However, little is known about the effects of altering altitudes on the morpho-physiological traits determining the commercial value of mango. Therefore, we systematically investigated a commercial mango cultivar at eight altitudes ranging from 680 to 1400 masl to check the environmental impact on morpho-physiological attributes and volatile compounds using analysis of variance, principal component analysis, clustering, and correlation. We observed an increase in fruit weight and size from 680 to 1000 masl elevation and a gradual decrease at higher altitudes above 1000 msl. In contrast, quality parameters, including total soluble solids and total sugar, decreased with the increase in altitude, while the total acid increased with the increase in altitude. Moreover, we characterized the dried fruit, pericarp, and sarcocarp for aromatic compounds and identified 110 volatile compounds. The accumulation pattern of the volatiles suggested a considerable influence of environmental factors associated with altering altitudes. However, there was no clear trend in the volatile accumulation at different altitudes. We further determined the ten most frequently occurring volatiles at different altitudes and tissues. For instance, Alpha-Guaiene was only identified at 1000–1215 masl altitudes in dried fruit, while Beta-Ocimene showed the highest accumulation at 900 masl in dried fruit and pericarp. Together, our study provides clues on the impact of the altitude on mango fruit yield and quality attributes, which will guide future agronomic practices.