Vacuolar processing enzyme (VPE) is a cysteine protease responsible for vacuolar proteins’ maturation and regulation of programmed cell death (PCD). Four isoforms of Arabidopsis thaliana VPEs were identified previously, but only the functions of βVPE, γVPE, and δVPE were determined. The specific function of a gene is linked to the cis-acting elements in the promoter region. A promoter analysis found repetitive drought-related cis-elements in αVPE, which highlight its potential involvement in drought regulation in A. thaliana. The further co-expression network portraying genes interacting with αVPE substantiated its drought-regulation-related function. Expression of αVPE was upregulated after drought treatment in A. thaliana. To confirm the role of αVPE, a loss of function study revealed that αVPE knockout mutants remained green compared with WT after drought treatment. The mutants had reduced proline activity, decreased sucrose content, and lower MDA content, but increased photosynthetic pigments, indicating that αVPE negatively regulates drought tolerance in A. thaliana. Taken together, our findings serve as important evidence of the involvement of αVPE in modulating drought tolerance in A. thaliana.

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most threatening fungal diseases affecting banana plantations across the globe. It was first discovered in Australia in 1874 and has now spread to numerous different regions in the world hinting at the persistency of the pathogen. Various management strategies have been devised aiming mainly on improving the plant’s tolerance or suppressing the infection. Fungicide is commonly used to control the disease spread, but it does not provide total protection to the plants besides displaying selective effectiveness on certain Foc strains. Alternatively, farmers apply crop rotation, rice hull burning, biological soil disinfestation, and compound-supplemented soil in their banana plantations. Studies have also shown that certain biocontrol agents manage to curb the disease threat. Selection of somaclonal variants and genetic manipulation via induced mutagenesis and transformation are also among the alternatives that have been implemented in producing Fusarium-tolerant and Fusarium-resistant banana plants. This chapter will describe Fusarium epidemics in banana, the effectiveness and challenges of different management approaches, as well as the future alternatives that can be adopted by taking advantages of the latest advances in omics technologies.