Plant NAC (NAM, ATAF1/2, and CUC2) family is involved in various development processes including Programmed Cell Death (PCD) associated development. However, the relationship between NAC family and PCD-associated cotton pigment gland development is largely unknown. In this study, we identified 150, 153 and 299 NAC genes in newly updated genome sequences of G. arboreum, G. raimondii and G. hirsutum, respectively. All NAC genes were divided into 8 groups by the phylogenetic analysis and most of them were conserved during cotton evolution. Using the vital regulator of gland formation GhMYC2-like as bait, expression correlation analysis screened out 6 NAC genes which were low-expressed in glandless cotton and high-expressed in glanded cotton. These 6 NAC genes acted downstream of GhMYC2-like and were induced by MeJA. Silencing CGF1(Cotton Gland Formation1), another MYC-coding gene, caused almost glandless phenotype and down-regulated expression of GhMYC2-like and the 6 NAC genes, indicating a MYC-NAC regulatory network in gland development. In addition, predicted regulatory mechanism showed that the 6 NAC genes were possibly regulated by light, various phytohormones and transcription factors as well as miRNAs. The interaction network and DNA binding sites of the 6 NAC transcription factors were also predicted. These results laid the foundation for further study of gland-related genes and gland development regulatory network.

Accurately predicting the crown photosynthesis of trees is important to understand the tree growth status and carbon circle in terrestrial ecosystem. However, modeling the photosynthetic carbon dioxide (CO ₂ ) response curves for individual tree are still challenging due to the complex canopy structure and changeable environmental conditions. Therefore, taking 16-old year Larix principis-rupprechtii Mayr . as the research material, the dynamic CO ₂ response models of photosynthesis, including rectangular hyperbolic model (RHM), the non-rectangular hyperbolic model (NRHM) and the modified rectangular hyperbolic model (MRHM), were used to simulate CO ₂ response curves of the crown. The fitting accuracy of the models depend on the comparison of determinants coefficients ( R ² ), mean square errors ( MSE ) and Akaike information criterion ( AIC ). The results showed that the mean value of R ² ( R ² =0.9939 ∼ 0.9964) of MRHM was the highest, whereas MSE value ( MSE =0.2185∼0.2627) and AIC value ( AIC =-13.18∼-8.03) were the lowest. The CO ₂ -saturated gross photosynthetic rate ( A _max ) and the saturation point ( C _i SP ) obtained by MRHM were closest to the measured value respectively. Therefore, the MRHM fitted the CO ₂ response data well, and calculated the photosynthetic parameters directly and accurately, the fitted result showed α, A _max , C _i SP, C _i CP and R _P were 0.04, 7.51 μmol·m ^-2 s ^-1 , 938.97 μmol·m ^-2 , 67.54 μmol·m ^-2 and 0.60 μmol·m ^-2 s ^-1 , respectively. In addition, the difference on the photosynthetic CO ₂ response parameters values showed somewhat among different layers and orientations. In all, all data suggested that the modified rectangular hyperbolic model (MRHM) was an ideal model to fit the crown photosynthetic CO ₂ response curve of Larix principis-rupprechtii Mayr. These results are of great significance for parameter calibration of photosynthetic model and robust prediction of photosynthetic response in forest.

Upland cotton ( Gossypium hirsutum L.) is one of the most economically important crops worldwide due to the significant source of natural fiber, feed, oil and biofuel products. Cottonseed can also serve as an excellent source of edible protein and oil. However,the presence of gossypol in pigment gland has limited it utilization In the past few decades, some progress has been made in the understanding molecular mechanism of the formation of the pigment gland. However, little is known about the specific mechanism of pigment gland formation in cotton. In this study, the cDNA sequence of a ethylene transcription factor gene, designated GhERF105a, was cloned from upland cotton CCRI12. Sequence alignment revealed that GhERF105a gene contained a typical AP2/ERF domain of 61 amino acids, and belonged to the ERF subgroup of the ERF supfamily. It was highly expressed in the leaves and stems of glanded plants but had substantially lower expression of the glandless plants. GhERF105a, localized to the nucleus, could bind to GCC-box and DRE. Some development, phytohormone and stress related cis-elements were enriched in the promoters of GhERF105a/d . Split ubiquitin assays in yeast and BiFC experiments showed extensive interactions between GhERF105a and Gh_A07G1044. In addition, GhERF105a was highly similar with GhERF105d in the gene length, molecular weight, protein molecule, gene structure and expression pattern. The overall results suggested that GhERF105a might participate in the pigment gland formation and stree-response processes.