Zheng Zeng

Shoot regeneration is an important prerequisite for many plant transformation and genome-editing protocols, but responses can vary among commercial cultivars. We screened 43 Luffa cultivars, recorded as 21 ridged and 22 smooth types, on four MS-based media using seedling-derived cotyledon and cotyledonary-axis explants. At a common six-week endpoint, 10,433 of 10,517 explants formed callus (99.20%), 2074 showed browning (19.72%), and 353 produced a recognizable small shoot bud and/or young leaves (3.36%; descriptive 95% Wilson CI: 3.03–3.72%). Twenty-five cultivars were shoot-positive on at least one medium, whereas 18 were negative on all four. Cuihua2212 had the highest pooled response (60/250 (24.0%)). A cultivar-clustered, denominator-weighted binomial-family generalized estimating equation gave a global medium Wald χ²(3) of 7.48 (p = 0.058). In six exploratory pairwise comparisons, C exceeded D (OR: 2.51, 95% CI: 1.30–4.88; BH-adjusted q = 0.039). The medium-adjusted ridged/smooth OR was 2.54 (95% CI: 1.04–6.17), with substantial uncertainty and sensitivity to cultivar composition. Frequent callus formation, therefore, coincided with infrequent visible shoot recovery under the conditions tested. The screen identifies candidates for independent regeneration optimization; it does not establish a callus-derived shoot pathway, species-wide differences or transformation competence.

Garlic, originating in the mountains of Central Asia, has undergone domestication and subsequent widespread introduction to diverse regions. Human selection for adaptation to various climates has resulted in the development of numerous garlic varieties, each characterized by specific morphological and physiological traits. However, this process has led to a loss of fertility and seed production in garlic crops. In this study, we conducted morpho-physiological and transcriptome analyses, along with whole-genome resequencing of 41 garlic accessions from different regions, in order to assess the variations in reproductive traits among garlic populations. Our findings indicate that the evolution of garlic crops was associated with mutations in genes related to vernalization and the circadian clock. The decline in sexual reproduction is not solely attributed to a few mutations in specific genes, but is correlated with extensive alterations in the genetic regulation of the annual cycle, stress adaptations, and environmental requirements. The regulation of flowering ability, stress response, and metabolism occurs at both the genetic and transcriptional levels. We conclude that the migration and evolution of garlic crops involve substantial and diverse changes across the entire genome landscape. The construction of a garlic pan-genome, encompassing genetic diversity from various garlic populations, will provide further insights for research into and the improvement of garlic crops.

NAM, ATAF, and CUC (NAC) proteins are plant-specific transcription factors that play crucial roles in fiber growth by regulating the secondary wall thickening. In this study, a systematical investigation of NAC genes was performed in the genome of ramie, an important fiber crop, resulting in a total of 60 ramie NAC genes identified. Phylogenetic analysis of these 60 NAC members in conjunction with 111 Arabidopsis NAC proteins identified 11 subfamilies, three of which showed considerable contraction in the ramie genome. Ten ramie NAC genes were identified to encode the orthologs of Arabidopsis NAC regulators involved in the control of secondary wall biosynthesis. Of these ten genes, most showed relatively high expression in the stems, and eight displayed a differential expression between the barks from the top and middle section of the stems where fiber growth is under different stages. Furthermore, the overexpression of three of these ten NAC genes significantly promoted fiber growth in transgenic Arabidopsis. These results indicated that these ten NAC genes were associated with the fiber growth of ramie. This study provided an important basis for researching the regulatory mechanism of fiber growth.